Stage Triple Negative Breast Cancer Research Articles

Abstract PO4-08-10: Genetic mutations and associated rates of pathologic complete response among a diverse patient population with early stage triple negative breast cancer

Abstract Background: Combination treatment with chemotherapy and immunotherapy remains the standard of care for high risk, early-stage triple negative breast cancer (TNBC). Although the addition of immunotherapy improves rates of pathologic complete response (pCR) and event-free survival, approximately 50% of patients achieve pCR with neoadjuvant chemotherapy alone suggesting that some patients may safely avoid the potential toxicities of immunotherapy without compromising outcomes.1,2 Markers of immune activation including PD-L1 expression and tumor infiltrating lymphocytes have demonstrated prognostic significance; however, identifying a predictive biomarker to aid in selecting those patients most likely to benefit from immunotherapy remains an unmet need.3,4 Genetic mutations are suggestive of DNA susceptibility to damage and the role they may play as a potential marker of immune response is unclear.5,6 This study explores genetic analysis and mutation rates among a diverse cohort of patients with TNBC to identify patterns associated with and without pCR. Methods: We evaluated 105 women diagnosed with Stage I-III TNBC and treated with combination neoadjuvant chemotherapy and immunotherapy at Ochsner Cancer Center between December 2019 through June 2022. Exclusion criteria included ER+, PR+, HER2+, or unknown receptor status, no pembrolizumab in the neoadjuvant setting, no definitive surgery following neoadjuvant treatment, absence of documented race and age less than 18 years of age. Data was collected utilizing Epic Slicer Dicer program, in addition to chart review. Genetic analysis was performed using a variety of DNA-based next generation sequencing analysis platforms. Results: 91 patients met inclusion criteria. 17 patients were found to have pathogenic mutations (BRCA1/2, POLE and ATM), 38 patients had variants of undetermined significance (VUS) and 36 patients had neither. Among patients with pathogenic genetic mutations, 81.25% had a pCR following neoadjuvant treatment compared to 58.33% of those with a VUS and 47.06% of those with no known mutation (p=0.07). Before adjusting for age and stage, patients with a pathogenic mutation were 73% more likely to achieve pCR than those with no known genetic mutations (crude RR: 1.73, 95% CI: 1.13-2.65). After adjusting for age and stage, the relationship was not statistically significant (aRR: 1.15, 95% CI: 0.78-1.34). Among the 47 Black patients, 5 were found to have a pathogenic mutation and 29 had a VUS. 11 of the 39 White patients were found to have a pathogenic mutation while only 6 had a VUS. Across all genetic mutation categories, Black patients experienced lower rates of pCR than White patients. White patients with a known pathogenic mutation had the highest rate of pCR at 90.91%, while Black patients with no identified mutation had the lowest rate of pCR at 38.46%. The generalizability of these results may be limited due to small sample size. Conclusion: Our results demonstrating higher rates of genetic variants among patients achieving pCR regardless of race highlight the importance of better understanding how these variants correlate with tumor mutational burden (TMB) and further, the role this may play in predicting immune-response. Larger studies are needed to assess TMB as a predictive biomarker in early-stage TNBC as this may provide opportunities to further individualize treatment and minimize toxicity among this group of patients. Additionally, given differences in the prevalence of pathogenic mutations and VUS among Black patients, better understanding the relationship between mutation status and immune response is imperative to optimize outcomes in this high-risk population. Table. Citation Format: Caitlin Taylor, Melanie Sheen, Rabia Cattie, Victoria Chung, Melyssa Bratton, Meredith Lakey, Erin Biggs. Genetic mutations and associated rates of pathologic complete response among a diverse patient population with early stage triple negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-08-10.

Abstract PO1-03-06: Older patients with Early Stage Triple Negative Breast Cancer: The Memorial Sloan Kettering Cancer Center experience

Abstract INTRODUCTION Approximately 15% cases of TNBC are diagnosed in individuals over the age of 70. Older patients remain under-represented in clinical trials. We conducted a retrospective review of patients 70 years of age and older with stage I-III TNBC who were treated at Memorial Sloan Kettering Cancer Center (MSKCC), with the goal of describing the clinical practice patterns and outcomes. MATERIAL AND METHODS A retrospective record review of patients 70 years of age and older with a diagnosis of stage I-III TNBC between January 2015-December 2019 was performed. We report the data on the utilization of systemic chemotherapy and survival analyses. We compared patient characteristics by chemotherapy type using Wilcoxon rank sum test, Pearson’s Chi-squared test, and Fisher’s exact test. Overall Survival (OS), Breast Cancer Specific Survival (BCSS), and Recurrence Free BCSS (RF-BCSS) were examined using Cox proportional hazards models. All statistical analyses were conducted using R. RESULTS A total of 147 patients were included. The median age was 75 years (range 70-96). The number of patients with stage I, II, and III disease was 64 (44%), 66 (45%), 17 (12%), respectively. Twenty-five (18%) patients underwent comprehensive geriatric assessment. Out of total patients, 93 (63%) patients received systemic Chemotherapy (C) while 54 (37%) received no chemotherapy (NC). Patients receiving C were younger (median age 74 years with C vs. 78 years with NC, p< 0.001) and had a higher disease stage (Stage II-III: 66% (C) vs. 41% (NC), p=0.005). There were no significant differences in Activities of Daily Living (ADL) difficulty between both arms. Amongst, Instrumental ADL (IADL) assessment, patients in the NC group reported statistically significant greater difficulty with meal preparation (17% in NC and 4.3% in C, p=0.016). The most common reasons for not receiving chemotherapy were low-risk disease i.e. pT1aN0 or microinvasive (33%), patient preference (29%), and frailty per the treating oncologist (19%). Rate of mastectomy was higher in the NC group (35% in NC vs. 20% in C, p=0.029). Among the 32 patients who had radiation data, breast irradiation rates were higher in the C group (70% in C and 17% in NC, p=0.003). Thirty patients (20%) received neoadjuvant chemotherapy (NAC) and 65 (44%) received adjuvant chemotherapy. Anthracycline-based chemotherapy was the most common NAC (n=17, 57%). Patients who received Cyclophosphamide-Methotrexate-5-Fluorouracil (CMF) were older (age ≥75 years: 51% (CMF) vs. 17% (ACT),p=0.010), more likely treated in an adjuvant setting (87% CMF vs. 61% ACT, p=0.017), had earlier-stage disease (Stage 1: 54% (CMF) vs. 26% (ACT), p=0.028), and reported more ADL (31% in CMF vs. 0% in ACT, p=0.002) and IADL difficulties (31% CMF vs 4.3% in ACT, p=0.021). The use of Docetaxel/Cyclophosphamide (TC) and platinum-based regimens was low (8% and 5%, respectively). In the univariate analysis between the C and NC groups, there was no difference in OS (Hazard Ratio (HR) 0.78, 95% Confidence Interval (CI) 0.42-1.43; p=0.4), BCSS (HR 1.39, 95% CI 0.57-3.39; p=0.5), and RF-BCSS (HR 1.60, 95% CI 0.67-3.83; p=0.3). There was no difference in OS (HR 0.60, 95% CI 0.23-1.55; p=0.3), BCSS (HR 0.48, 95% CI 0.17-1.32; p=0.2), and RF-BCSS (HR 0.71, 95% CI 0.30-1.73; p=0.5) in patients receiving CMF vs. ACT. CONCLUSIONS In our single institutional experience, we observed that two-thirds of older patients with early-stage TNBC received systemic polychemotherapy. A third of patients with NC were very low risk (pT1a or microinvasive disease) which could explain lack of chemotherapy benefit in our study population. Use of CMF was more prevalent in patients aged ≥75, stage I disease, ADL/IADL difficulties, and in the adjuvant setting. We observed no difference in survival outcomes between the two chemotherapy regimens. CMF remains an efficacious option and a potentially viable alternative to ACT in TNBC, especially in the setting of early stage and advanced age. Citation Format: Jasmeet Singh, Diana Lake, West Dente-Ferguson, Yuan Chen, Fiona Erlich, Beatriz Korc-Grodzicki, Mark Robson, Larry Norton, W. Iris Zhi. Older patients with Early Stage Triple Negative Breast Cancer: The Memorial Sloan Kettering Cancer Center experience [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-03-06.

Abstract GS01-03: Adding atezolizumab to adjuvant chemotherapy for stage II and III triple-negative breast cancer is unlikely to improve efficacy: interim analysis of the ALEXANDRA/IMpassion030 phase 3 trial

Abstract Background: Early stage triple negative breast cancer (TNBC) is associated with a high risk of distant relapse. ALEXANDRA/IMpassion030 is a global, prospective, randomized, open-label, phase 3 trial that investigated the efficacy, safety and pharmacokinetic profile of adjuvant atezolizumab plus standard anthracycline/taxane chemotherapy (arm A) versus chemotherapy alone (arm B) in early-stage TNBC. Methods: ALEXANDRA/IMpassion030 (NCT03498716) aimed to randomize (1:1) 2300 patients with operable stage II-III TNBC, confirmed by central pathology review. Patients were stratified by type of surgery (breast conserving versus mastectomy), nodal status (0 versus 1-3 versus >=4 nodes), and centrally assessed PD-L1 status (IC 0 vs >=1% ). Adjuvant chemotherapy consisted of weekly paclitaxel 80 mg/m2 for 12 weeks followed by dose dense anthracycline (epirubicin 90 mg/m2 or doxorubicin 60 mg/m2) and cyclophosphamide 600 mg/m2 for 4 doses every 2 weeks given concomitantly with atezolizumab 840 mg every 2 weeks followed by maintenance atezolizumab 1200 mg every 3 weeks until completion of 1 year of atezolizumab (Arm A) or the same chemotherapy regimen (T-EC/AC) alone (Arm B). The primary endpoint was invasive disease-free survival (iDFS); secondary endpoints included, iDFS in the PD-L1 positive and lymph node-positive subpopulations, overall survival, safety, patient functioning and health related quality of life (HRQoL). On the 14th of November 2022, following an IDMC recommendation, the study accrual was temporarily stopped. In February 2023, the protocol was amended in order for the IDMC to perform an early interim analysis of efficacy and futility, at approximately 62% of the planned (390) iDFS events. The futility boundary was set to a Hazard Ratio (HR) > 1. Results: The IDMC recommendations of 15th March 2023 reported that the primary endpoint crossed the futility boundary, accrual to the study was permanently stopped and the experimental treatment was discontinued. Between August 2018 and November 2022, the study enrolled 2199 patients, with 1101 randomised to the atezolizumab arm (A) and 1098 to the control arm (B). At a median follow-up of 25.3 months, 239 (10.9%) iDFS events were observed in the 2199 enrolled patients; 127 versus 112 iDFS events were observed (61.3% of 390) in the A versus B arms respectively, HR 1.12, (95% confidence interval, CI, 0.87, 1.45). In the PD-L1 positive subgroup, (1567/2199 patients, 71.3%), 77 versus 73 iDFS events were observed in the A versus B arms respectively, HR 1.03, (95% CI 0.75, 1.42). Among patients with lymph node positive tumors (1066/2199 patients, 48.5%), 86 versus 66 iDFS events were observed in the A versus B arm respectively, HR 1.41, (95% CI 1.02, 1.96). Incidence of adverse events grade >=3 was 58.01% versus 48.15% in the A versus B arms, including death in 1.01% (11) and 0.55% (6) of patients, respectively. Conclusions: Crossing the pre-specified futility boundary of HR > 1 provides evidence that adjuvant atezolizumab is very unlikely to improve invasive disease-free survival when added to adjuvant anthracycline and taxane based chemotherapy in patients with stage II-III triple-negative breast cancer. With longer treatment exposure in the atezolizumab arm (A), adverse events were more frequent but consistent with the atezolizumab safety profile. No new or unexpected safety issue was identified. Citation Format: Michail Ignatiadis, Andrew Bailey, Heather McArthur, Sarra El-Abed, Evandro de Azambuja, Otto Metzger, Steve Chui, Max Dieterich, Thomas Perretti, Guenther Steger, Jacek Jassem, Soo Chin Lee, Michaela Higgins, José Zarbá, Marcus Schmidt, Henry Gomez, Angel Guerrero-Zotano, Luca Moscetti, Joanne Win Yang Chiu, Carter DuFrane, Vanessa Honvault, Rosa Altarcheh, Luciana Molinero, Andrew Ellingson, Elisabetta Munzone, Noa Efrat Ben-Baruch, Emilio Bajetta, Shinji Ohno, Seock-Ah Im, Gustavo Werutsky, Einav Gal-Yam, Xavier Gonzalez-Farré, Ling-Ming Tseng, William Jacot, Oleg Gluz, Zhimin Shao, Yaroslav Shparyk, Ivan Sinielnikov, Zimina Anastasia, Aleksandr Vasiliev, Esther Shearer-Kang, Eric Winer, Diogo Martins-Branco, Shona Fielding, David Cameron, Giuseppe Viale, Shigehira Saji, Richard Gelber, Martine Piccart. Adding atezolizumab to adjuvant chemotherapy for stage II and III triple-negative breast cancer is unlikely to improve efficacy: interim analysis of the ALEXANDRA/IMpassion030 phase 3 trial [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr GS01-03.

Abstract PO2-03-12: Dose-Dense Doxorubicin plus Cyclophosphamide (ddAC) and Impact of Chemotherapy Sequence in a Modified KEYNOTE-522 Regimen for Neoadjuvant Treatment of Triple Negative Breast Cancer: Real World Experience

Abstract Background: Standard of care systemic treatment for early stage triple negative breast cancer (TNBC) consists of neoadjuvant chemoimmunotherapy based upon the results of KEYNOTE 522 (KN-522). The KN522 regimen utilized q3week dosing for doxorubicin plus cyclophosphamide (AC); however, dose-dense AC (ddAC) has shown superior OS compared to q3week AC in anthracycline and taxane-based regimens (per CALGB 9741 and EBCTCG analyses). We now present a retrospective study of patients treated with ddAC in a modified KN-522 regimen and report real world feasibility, safety, and efficacy endpoints, including exploration of whether sequencing ddAC before or after carboplatin/paclitaxel (CbT) plus pembrolizumab impacts outcome. Methods: Patients with TNBC treated at MSK from August 2021 to September 2022 with a preoperative KN-522 regimen were eligible for inclusion. Clinicopathological and demographic data were obtained from chart review. The primary goal of this study was to describe pathologic complete response (PCR) rate, incidence of treatment-related toxicities resulting in treatment delays, and type of toxicity. Treatment delays for toxicity were defined as a >1 week delay in treatment or discontinuation of a treatment regimen component due to a medical reason. Exploratory analysis was conducted to assess efficacy and toxicity of ddAC before or after CbT as well as rate of GCSF usage with CbT. Baseline characteristics, incidence and type of delays, and treatment outcomes were compared between ddAC first and CbT first using two sample non-parametric tests. Results: 129 TNBC patients met eligibility as defined above. Median age of diagnosis was 50. Clinical stage at diagnosis: Stage I 6%, Stage II 83%, and Stage III 11%. 128 patients received ddAC and 1 patient received AC q3week. Of the 128 patients, 54% received ddAC first while 46% received CbT first. Overall PCR rate of 56%. Treatment-related toxicity leading to chemotherapy delays was 61% and immunotherapy delays was 30%. Most chemotherapy delays were due to cytopenias (79%), with neutropenia (66%) most common. Adrenal insufficiency (4%) and hepatitis (5%) were the most common immune-related toxicities leading to delays. Overall, PCR rate was not affected by chemotherapy delays (No Delay 50% vs. Delay 60%, RR 0.83, 95%CI 0.60-1.15, p=0.25) or immunotherapy delays (No Delay 56% vs. Delay 58%, RR 0.96, 95%CI 0.69-1.33, p=0.81). Exploratory analysis comparing sequencing of ddAC vs CbT first showed incidence of CbT delays was 58% in patients treated with ddAC first and 27% in CbT first. Incidence of ddAC delays was 3% in patients treated with ddAC first and 7% in CbT first. Incidence of delays in both ddAC and CbT was 9% in ddAC first and 10% in CbT first. There was no difference in PCR rate (ddAC 55% vs. CbT 58%, RR 0.96, 95%CI 0.70-1.30, p=0.77) or rate of immunotherapy delays (ddAC 32% vs. CbT 34%, RR 0.93, 95%CI 0.55-1.57, p=0.79) based on sequence of chemotherapy. However, ddAC first compared to CbT first correlated with a significant increase in the incidence of overall treatment delays (ddAC 70% vs. CbT 51%, RR 1.37, 95%CI 1.02-1.84, p=0.03), use of GCSF during CbT (ddAC 55% vs. CbT 34%, RR 1.60, 95%CI 1.06-2.45, p=0.02), and treatment-limiting cytopenias at any time point before surgery (ddAC 59% vs. CbT 31%, RR 1.95, 95%CI 1.26-3.00, p=0.001). Conclusions: These real world data support the feasibility and tolerability of ddAC in a modified KN522 regimen. Exploratory analysis on sequencing of ddAC vs. CbT first in this regimen suggests that efficacy is comparable, yet ddAC first is significantly associated with higher rates of treatment delays and cytopenias. Overall, our experience suggests ddAC is a safe and viable modification to KN-522, and sequencing ddAC after CbT may reduce the risk of treatment induced cytopenias. Citation Format: Nicholas Mai, Sara Myers, Sherry Shen, Stephanie Downs-Canner, Yuan Chen, Tiffany Traina, Nour Abuhadra. Dose-Dense Doxorubicin plus Cyclophosphamide (ddAC) and Impact of Chemotherapy Sequence in a Modified KEYNOTE-522 Regimen for Neoadjuvant Treatment of Triple Negative Breast Cancer: Real World Experience [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-03-12.

Abstract PO3-25-11: Unprecedented responses to neoadjuvant sequential administration of Tocilizumab followed by cisplatin/docetaxel for locally advanced triple negative breast cancer patients

Abstract Background: Triple negative breast cancer (TNBC) remains a challenge for clinicians due to its aggressive behavior and scarcity of effective treatment. Interleukin 6 (IL-6) is well known to contribute to poor therapeutic gain, tumor relapse and aggressive tumor growth. Here we have explored targeting the IL-6 signaling pathway by Tocilizumab (Actemra) as a new potential therapeutic approach for the treatment of TNBC. Methods: The study population includes thirty (30) patients with (T2-T4, N0-3) stage (IIB-III) TNBC treated uniformly with Tocilizumab followed with cisplatin/docetaxel according to a traditional 3+3 design using a sentinel patient at each cohort. Eligible patients received Tocilizumab on day 1 followed by cisplatin/docetaxel on day 2 every 4 weeks for a total of six cycles. The primary end points were pathological complete response in breast and axilla (pCR) (ypT0/ypN0) and assessment for tolerability/toxicities profiles. Additionally, the status of the BRCA1 and BRCA2 genes was determined in all patients. Results: Eligible patients who were enrolled in this phase I/II trial had a median age of 42 years, with 63% premenopausal and 67% had nodal involvement at base line. The median tumor size was 45 mm (range 25-150 mm), stage III A/B 26% and stage IIIC 50%. Germline BRCA1/2 mutations represented 27%. The overall pCR and (RCB class 0+1) were 66% and 69%, respectively. Interestingly, pCR reached 81% in axilla, and 100% in patients with tumors bearing BRCA1/2 mutations. Interestingly, tocilizumab affected the blood level of several pro-carcinogenic cytokines. Conclusions: To our knowledge this novel therapeutic strategy is the first to report the inhibition of a cytokine signaling (a new class of biological therapy) in combination with chemotherapy for the intricate and hard-to-treat TNBC patients with unprecedented responses and acceptable tolerability/toxicities, which merits further investigation. Pending Patents: US Patent Application No. 18/122,839 European Patent Application No. 23 162 694.6 Citation Format: Taher Al-Tweigeri, Noura Alraouji, Asma Tulbah, Syed Akhtar, Meshari Alzahrani, Saleh Najjar, Dahish Ajarim, Kauser Suleman, Adher Al Sayed, Abdelilah Aboussekhra. Unprecedented responses to neoadjuvant sequential administration of Tocilizumab followed by cisplatin/docetaxel for locally advanced triple negative breast cancer patients [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-25-11.

Abstract RF02-07: Precocious modulation of metabolic and immunological parameters predicts tumor response to fasting-mimicking diet plus chemotherapy in patients with early stage TNBC

Abstract Background: Preclinical studies showed that severely calorie restricted fasting-mimicking diets (FMDs) enhance the antitumor efficacy of chemotherapy (CT) or immunotherapy (IO) in murine triple negative breast cancer (TNBC) models. These effects are mediated by a combination of blood glucose reduction and positive immunomodulatory effects. Moreover, combining fasting and metformin produced synergistic anticancer effects in a broad range of tumor models. The BREAKFAST trial was designed to investigate if FMD, plus/minus metformin, could increase the antitumor activity of neoadjuvant CT in patients with stage I-III TNBC. Methods: BREAKFAST (NCT04248998) is a randomized, non-comparative, phase II, pilot trial that enrolled stage I-III (cT>1 cm) TNBC patients (pts) candidate to receive 4 cycles of neoadjuvant CT with doxorubicin-cyclophosphamide every 3 weeks, followed by 12 cycles of weekly paclitaxel. Pts were randomized 1:1 to receive: CT plus 5-day FMD every 3 weeks, up to 8 cycles (arm A); CT plus FMD plus daily metformin (1700 mg) (arm B). The primary study endpoint was the rate of pCR in either experimental arm. Secondary/exploratory endpoints included safety, compliance, and biomarker analyses based on blood metabolomics and tumor transcriptomics analyses at different timepoints. Results: Between June 2020 and February 2022 we enrolled 30 pts. Then, the study was interrupted after the introduction of chemo-immunotherapy (CT-IO) as a standard neoadjuvant therapy for early stage TNBC pts. Among 30 pts, 13 were treated with CT plus FMD, while 17 pts received CT plus FMD plus metformin. Overall, pCR rate was 56.6%, i.e., significantly higher than pCR rates reported with anthracycline-taxane CT alone in previous phase II/III trials (26-39%), with no significant differences among treatment arms (p=0.49). The FMD acutely reduced blood glucose, insulin and LDH levels, which reflects a reduction in systemic and/or tumor glucose metabolism. Of note, precocious LDH reduction was more pronounced in patients undergoing pCR. RNA-seq analysis of tumor samples revealed a significant downmodulation of glycolysis and TCA cycle pathways after one treatment cycle, paralleled by an increase of intratumor activated T cells, memory T cells and NK cells, as estimated by deconvolution analyses of tumor transcriptomic data. Of note, these changes were observed only in patients achieving pCR. While intratumor metabolic changes were similar in the two treatment arms, the modulation of intratumor immunity was more pronounced in patients not receiving metformin. Conclusion: Preoperative CT plus cyclic FMD (plus/minus metformin) results in excellent pCR rates in localized TNBC patients. Early on-treatment downregulation of systemic and intratumor metabolic parameters related to glucose metabolism predicts pCR, and this is independent of metformin use. Based on results of this study, we recently initiated a large, multicentric trial, namely the BREAKFAST-2 (NCT05763992) study, which will investigate if adding cyclic FMD to neoadjuvant CT-IO increases pCR rates in ~ 145 pts with stage II-III TNBC. Citation Format: Francesca Ligorio, Giovanni Fucà, Andrea Vingiani, Fabio Iannelli, Riccardo Lobefaro, Leonardo Provenzano, Lucrezia Zanenga, Cristina Ferraris, Antonino Belfiore, Silvia Brich, Alessia Bertolotti, Gianfranco Scaperrotta, Catherine Depretto, Antonia Martinetti, Elisa Sottotetti, Paola Antonia Corsetto, Giulia Valeria Bianchi, Giuseppe Capri, Secondo Folli, Saverio Minucci, Marco Foiani, Massimiliano Pagani, Giancarlo Pruneri, Filippo De Braud, Claudio Vernieri. Precocious modulation of metabolic and immunological parameters predicts tumor response to fasting-mimicking diet plus chemotherapy in patients with early stage TNBC [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr RF02-07.

Abstract PO2-17-12: Phase I Trial of alpha-lactalbumin vaccine in high risk operable triple negative breast cancer (TNBC) and patients at high genetic risk for TNBC

Abstract Background: Triple-negative breast cancer (TNBC) has a poor prognosis and may be associated with germline mutations. α-Lactalbumin (aLA) is expressed in lactating breasts but not at other times or in other tissues. Expression of aLA is found in 70% of TNBC (PMID: 27322324) so could be an immunologic target for TNBC based on the “retired protein hypothesis” (PMID: 31926646). In pre-clinical studies, vaccination with aLA provided protection from development of autochthonous tumors in transgenic murine models of breast cancer and inhibited growth of established 4T1 transplantable breast tumors in BALB/c mice (PMID: 20512124). Methods: To determine the safety and immunogenicity of aLA, patients with early stage TNBC are being entered in a Phase I trial of aLA with GMP-grade zymosan adjuvant in Montanide ISA 51 VG vehicle. Subjects receive 3 vaccinations given once every 2 weeks. Events of Common Terminology Criteria for Adverse Events (CTCAE) grade ≥ 2 are considered dose-limiting toxicities (DLTs). Results: CTCAE toxicity by dose level is summarized below. All DLTs were injection site reactions, with ulceration and need for incisional drainage representing the grade 3 events. Seven (7) of 10 patients assayed to date have met protocol specified definitions of an immune response based on ELISpot assays to determine frequencies of T cells producing IFNγ and IL-17 in response to recombinant aLA. Assays for an additional 6 patients will be available in September 2023. Conclusion: Dose level ≤ 2 appears to be the maximum tolerated dose. Based on immune response, additional intermediate dose levels may be studied. An additional cohort of patients receiving concurrent anti-PD1 treatment is being accrued. Accrual of patients with BRCA1/2 or PALB2 mutations planning to undergo prophylactic mastectomy is beginning in order to define the toxicity and immunologic effects in this group and to determine whether inflammatory changes from occult lactational foci will be produced. Funding Source: Department of Defense (W81XWH-17-1-0592 and W81XWH-17-1-0593) Table 1 Worst Toxicity by Dose Level Citation Format: Justin Johnson, Emily Rhoades, Holly Levengood, Halle Moore, Megan Kruse, Erin Roesch, Jame Abraham, Brenna Elliott, Rachel Swartz, Holly Pederson, Elena Haury, Azka Ali, Tiffany Onger, Andrew Sciallis, Zahraa Al-Hilli, Wei Wei, Thaddeus Stappenbeck, George Budd. Phase I Trial of alpha-lactalbumin vaccine in high risk operable triple negative breast cancer (TNBC) and patients at high genetic risk for TNBC [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-17-12.

Abstract PO4-03-07: The impact of chemotherapy relative dose intensity on pathological complete response in patients with triple negative breast cancer treated with neoadjuvant chemotherapy

Abstract Background: Neoadjuvant chemotherapy (NACT) is the preferred treatment approach for early-stage triple negative breast cancer (TNBC). Achieving pathologic complete response (pCR) after NACT is associated with improved event-free survival and overall survival in patients with TNBC. Major research efforts have been deployed to identify predictive biomarkers for pCR in TNBC. However, the values of chemotherapy (CT) relative dose intensity (RDI) in predicting pCR remain unclear. Methods: A retrospective analysis was conducted among 96 consecutive patients with early stage TNBC who received NACT between February 2018 and January 2023 at the University of Naples Federico II (Naples, Italy). Patients’ demographics, clinical-pathological features, and type of CT schedules were retrieved from electronic medical records. pCR was defined as the absence of residual invasive or in situ carcinoma in primary tumor and/or lymph nodes, upon chemotherapy administration. RDI was calculated as the ratio of delivered to planned CT dose intensity. RDI was defined as low if < 85% or high if ≥85%, respectively. Univariate and multivariate logistic regression were used to evaluate the association between age, tumor stage, RDI, CT regimen dose type, and pCR. Results: All patients were included in the analysis. Median age at diagnosis was 51 years (range 28-75). Sixty-five (68%) and 31 (32%) patients were diagnosed with stage II and stage III TNBC, respectively. Nineteen (19%) patients received a sequential schedule of anthracycline plus cyclophosphamide (AC) and a taxane (T). Sixty-one (64%) patients received AC followed by concurrent carboplatin-paclitaxel (CaP). Sixteen (17%) patients received the anti-PD1 pembrolizumab in addition to ACCaP chemotherapy backbone (ACCaP-Pem). Fifty-four (56%) patients received a dose-dense AC-based CT. A pCR was achieved in 59 (61%) patients. Interestingly, patients who received a dose-dense AC based neoadjuvant CT had higher chance to achieve a pCR compared with those treated with a non dose-dense AC based CT (70% vs 46%, p = 0.03). Overall, 79 (82%) and 17 (18%) patients received a RDI high and RDI low CT, respectively. No difference in terms of age, body mass index, performance status, tumor stage, type of chemotherapy was observed between the two groups (Table 1). At univariate analysis RDI high (OR 5.18, 95%CI: 1.65-16.31, p=0.005) and dose dense AC-based CT (OR 2.42, 95%CI: 0.18-0.97, p=0.04) were significantly associated with pCR. In a multivariate model including RDI, age, tumor stage, and AC regimen dose type, RDI was the only variable independently associated with pCR (OR 4.60, 95% CI: 1.40-15.06, p = 0.01). Conclusion: A chemotherapy RDI≥ 85% independently predicts pCR in early stage TNBC patients treated with standard NACT. In our cohort, one in five patients received a suboptimal chemotherapy dose intensity affecting at least in part tumor response. Studies with larger TNBC patient populations are warranted to confirm the impact of RDI on pCR and long-term outcomes. Table 1 Citation Format: Roberto Buonaiuto, Giuseppe Neola, Aldo Caltavituro, Paola Trasacco, Federica Pia Mangiacotti, Giovanna Pecoraro, Matteo Lambertini, Erica Pietroluongo, Pietro De Placido, Sabino De Placido, Valeria Forestieri, Mario Giuliano, Grazia Arpino, Carmine De Angelis. The impact of chemotherapy relative dose intensity on pathological complete response in patients with triple negative breast cancer treated with neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-03-07.

Abstract PO2-13-04: Single cell characterization of senescent CD8+ T cell promotes immunotherapy resistance in early-stage triple-negative breast cancer

Abstract Background: Immune checkpoint blockade (ICB) has been explored in triple-negative breast cancer (TNBC) and has been proven to improve patient survival in advanced TNBCs (IMpassion130) or increase the pathological complete response rate in early TNBCs (KEYNOTE522). However, ICB could only benefit a subset of patients, highlighting the urgent need to optimize patient selection. Unlike in advanced TNBCs, a predictive biomarker for ICB in early TNBCs is still lacking. The main reason might be that previous studies neglected the heterogeneity of tumor ecosystems between early and advanced TNBCs. There is an urgent need to understand the unique ecosystem of early-stage TNBC and develop biomarkers for precision immunotherapy. Objective: This study aims to characterize the micro-loop associated with the immune efficacy of early TNBC, so as to explain the mechanisms behind the differences in early and late efficacy markers, identify efficacy markers in early TNBC immunotherapy, and search for clinical targeting strategies to sensitize TNBC for neoadjuvant therapy. Methods: We conducted an in-depth analysis of 32 single-cell transcriptomes, comprising 26 early-stage TNBC enrolled in prospective clinical trials (NCT04418154 and NCT04613674), receiving neoadjuvant chemotherapy alone (n=8) or combined with anti-PD1 (n=18), and 6 advanced TNBC. We analyzed the microenvironmental differences between early and advanced tumors, and between different treatment response groups in early stages, and identified a subpopulation of cells specific to early stages and associated with immunotherapeutic efficacy. We used mIHC, flow-through, and validated the presence of this cell in clinical samples. We also explored its predictive performance on four independent cohorts of TNBCs with ICB treatment (GSE194040, NCT04129996, GSE169246, GSE124821). Furthermore, to understand the impact of ISG+ T cells on immunotherapy efficacy and explore targeting strategies, we employed a multi-faceted approach to assess their tumor-killing ability, response to Anti-PD1 treatment, and sensitization effect of drugs targeting ISG+ T cells. ISG+ T cells were sorted using flow cytometry for further experiment. In vitro, we established a co-culture model of primary TNBC patients-derived organoid (PDO) and tumor infiltrated CD8+T cells and evaluated the tumor cell viability as well as T cell cytotoxicity. In vivo, we established TS/A tumor cell bearing BalB/c mouse and E0771 tumor cell-bearing C57BL mouse and measured tumor size and tumor microenvironment by flow cytometry. Results: We obtained 236,017 high-quality cells and identified cell subsets across 32 samples with different stages, treatments and responses. We then uncovered an enriched subset of interferon-induced (ISG+) CD8+ T cells specific to early TNBC, serving as a predictive factor for ICB resistance. Mechanistically, the upregulation of the IFN pathway in early-stage TNBC triggers a transition in ISG+ CD8+ T cells, resulting in cellular senescence, diminished cytotoxicity, and impaired response to ICB. Encouragingly, we made a noteworthy discovery that Nicotinamide mononucleotide, an anti-aging drug, effectively restores the functionality of ISG+ CD8+ T cells, amplifying immunotherapy sensitivity. Conclusions: This study provided a comprehensive single-cell transcriptome atlas of early-stage TNBC and depicted stage-related ISG+CD8+ T cell for predicting ICB response in early TNBC. We emphasize the critical role of T cell dysfunction prompted by cellular senescence in driving ICB resistance during the early stages of TNBC and propose an approach for sensitizing immunotherapy with aging drugs. Citation Format: Tong Fu, Yi-Yu Chen, Xi Jin, Yi-Zhou Jiang, Zhi-Ming Shao. Single cell characterization of senescent CD8+ T cell promotes immunotherapy resistance in early-stage triple-negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-13-04.

Abstract PO3-03-07: Patterns of Chemotherapy Utilization among Elderly Patients with Early-Stage Triple-Negative Breast Cancer

Abstract Background: Patterns of adjuvant and neoadjuvant chemotherapy use among patients with breast cancer have changed over time. Historically, adjuvant chemotherapy has been the standard treatment approach for patients with triple-negative breast cancer after surgical resection, aiming to eliminate any remaining cancer cells and reduce the risk of recurrence. Advancements in treatment strategies, research findings, and clinical guidelines have contributed to shifts in cancer care approaches, with an increase in the use of neoadjuvant chemotherapy. In this study, we explore chemotherapy utilization in a large cohort of elderly patients diagnosed with early-stage triple-negative breast cancer (TNBC). Methods: Data were obtained from the SEER- and Texas Cancer Registry (TCR)-linked Medicare databases. We identified female patients aged 66 years or older, diagnosed with early-stage (localized or regional disease) TNBC between 2010 and 2017 with claims until 2019. We identified the use of chemotherapy using HCPCS codes from outpatient and physician’s carrier claims. We used descriptive statistics and analyzed overall chemotherapy utilization and time trends of neoadjuvant versus adjuvant use via the Cochran-Armitage trend test, and evaluated factors associated with chemotherapy use via logistic regression models. This study adhered to the STROBE reporting guidelines for cohort studies. Results: Among 8,848 patients with localized or regional stage TNBC (median age 74) a total of 5,159 (58%) were treated with chemotherapy. The rate of chemotherapy utilization increased yearly from 52% in 2010 to 66% in 2017 (p< 0.001). After multivariable adjustment, any chemotherapy use was associated with recent year of diagnosis (OR=1.77; 95%CI 1.54-2.04), regional stage compared to localized (OR=3.78; 95%CI 3.34-4.27), and Northeastern region compared to South (OR=1.2; 95%CI 1.06-1.37). Conversely, decreased chemotherapy use was associated with age ≥76 (OR=0.24; 95%CI 0.2-0.27), being single (OR=0.76; 95%CI 0.67-0.86), and higher comorbidity score (OR=0.69; 95%CI 0.61-0.78). Among chemotherapy-treated patients, 3,808 (73.8%) received it in the adjuvant setting, 722 (14.0%) received it in the neoadjuvant setting, and 629 (12.2%) received chemotherapy both preoperatively and postoperatively. Among those who were treated with any chemotherapy, the percentage of patients treated with neoadjuvant chemotherapy increased from 15.2% in 2010 to 37.4% in 2017 (p< 0.001). Among patients treated with chemotherapy, neoadjuvant chemotherapy use was associated with recent year of diagnosis (OR=3.38; 95%CI 2.77-4.12), regional stage (OR=3.28; 95%CI 2.86-3.77), and inversely associated with older age (OR=0.77; 95%CI 0.64-0.94), non-White, non-Hispanic, non-Black race or ethnicity (OR=0.64 95%CI 0.45-0.94), non-metro area (OR=0.61; 95%CI 0.5-0.74), and Northeastern region (OR=0.66; 95%CI 0.56-0.78). Conclusion: Our study highlights the significant changes in patterns of adjuvant and neoadjuvant chemotherapy use among elderly patients with early-stage TNBC. We observed an increasing trend in chemotherapy utilization, with a notable shift from adjuvant to neoadjuvant treatment. This transition reflects the evolving landscape of cancer care and the adoption of more personalized approaches to treatment, with increased utilization of neoadjuvant chemotherapy offering opportunities for better risk assessments and tailored treatment strategies. Citation Format: Catalina Malinowski, Xiudong Lei, Sharon Giordano, Marianna Chavez. Patterns of Chemotherapy Utilization among Elderly Patients with Early-Stage Triple-Negative Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-03-07.

Abstract 5183: Retrospective analysis of CCNG1 expression in tumors, a novel biomarker in development for partnering with DRG-101, a tumor targeted retrovector encoding a CCNG1 inhibitor gene

Abstract Background: CCNG1, a non-canonical cyclin, is a novel biomarker in development for partnering with DRG-101 (DeltaRex-G), a tumor targeted retrovector encoding a CCNG1 inhibitor gene. Expanded access using DRG-101 is currently open for an intermediate-size population of advanced pancreatic cancer, sarcoma and carcinoma of breast (NCT04091295). Therefore, it is important to identify patients who might respond favorably to DRG-101 gene therapy. Previously, we reported that CCNG1 expression is enhanced in sarcoma tumors (Ann Oncol 34, 1980P, 2023). In this report, we have expanded the analysis to 137 patients with all cancer types and describe patients with known CCNG1 expression levels who have been treated with DRG-101. Methods: Archived formalin-fixed paraffin-embedded (FFPE) tumor specimens (n=137) from patients who were followed at the Sarcoma Oncology Research Center were collected, processed, and subjected to RNA sequencing. Briefly, RNA-seq libraries were sequenced to generate 50 million reads, aligned using Kallisto v0.42.4 to GENCODE v23 transcripts with default parameters. Only protein-coding, IGH/K/L- and TCR-related transcripts were retained for downstream processing, resulting in 20,062 protein-coding genes. Gene expression levels in patients of the reference cohorts are categorized as low/medium/high, defined by Low = < 17%; Medium-high = 50%-83%; Medium-low = 17%-49%; High = >83%. Results: Seventy women and sixty-seven men, ranging in age from 16 to 87 years, were studied. All tumors showed enhanced CCNG1 expression. Thirty (22%) tumors exhibited high CCNG1 expression, 53 (39%) showed medium-high CCNG1 expression, 48 (35%) displayed medium-low CCNG1 expression, and six (4%) had low CCNG1 expression. One hundred (73%) patients had metastatic disease, and 37 (27%) had localized disease. There was no correlation between CCNG1 expression and disease stage. As a result of these findings, the FDA-CBER authorized the use of DRG-101 in an Expanded Access program as platform therapy upon which one or more FDA approved cancer drugs/immunotherapies may be added. Historically, one patient with metastatic pancreatic cancer, one with early stage, HR+ HER2+ invasive breast cancer and one with early stage triple negative breast cancer are alive 15, 3 and 2.5 years in sustained remission with DRG-101 therapy, and had 24%, 23% and 74% CCNG1 tumor expression levels respectively. Five patients with advanced pancreatic cancer, sarcoma and breast cancer and known CCNG1 expression levels are currently being treated with DRG-101. Conclusions:(1) 100% of tumors tested showed enhanced CCNG1 expression at varying levels, and (2) the use of DRG-101 in combination with FDA approved cancer drugs/immunotherapies is on-going for an intermediate size population of advanced pancreatic cancer, sarcoma and carcinoma of breast. Citation Format: Nadezhda Omelchenko, Vaishali Kumar, Samantha Jeffrey, Grace Haroun, Don Brigham, William H. Isacoff, Sant Chawla. Retrospective analysis of CCNG1 expression in tumors, a novel biomarker in development for partnering with DRG-101, a tumor targeted retrovector encoding a CCNG1 inhibitor gene [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5183.

Breast Conserving Surgery (BCS) is Superior to Mastectomy in Early Stage Triple Negative Breast Cancer (TNBC) a Comparative Study

Background: Breast cancer is the most prevalent form of cancer in women worldwide and the second-leading cause of death from cancer in women. Because the estrogen receptor, progesterone receptor, and HER2 are not expressed, triple-negative breast cancer (TNBC) has an aggressive clinical history. The highest rates of recurrence and survival, higher average grades, and larger tumor sizes at diagnosis are all characteristics of TNBC. Objective: To compare between breast conserving surgery (BCS) and mastectomy patients with early stage Triple negative breast cancer (TNBC). Materials and Methods: We conducted a comparative retrospective monocentric study that evaluated TNBC patients treated with upfront surgery at CMH Dhaka, CMH Bogura and Kurmitola General Hospital, Dhaka. The observation period was from 1 January 2021 to 31 December 2022. All patients received biopsy to obtain the pathological tissue before treatment, and their immunohistochemical results met the diagnostic criteria for TNBC. Study patients divide din to two group 40 surgeries with primary site were categorized as receiving BCS and other hand 40 surgeries with categorized as receiving mastectomy. BCSS and OS were the primary outcomes of our study. Results: Tumor grade II, tumor size >20.0 mm and lymph node 2 were significantly associated with breast cancer-specific survival. Tumor size >20.0 mm and lymph node 2 were significantly associated with TNBC survival. Conclusion: TNBC is a breast cancer type that is aggressive and has a bad prognosis. With regard to breast cancer-specific survival, advanced age, being single, left side of laterality, tumor grades II and III, large tumor size, and lymph node 2 were all substantially related.

The impact of germline BRCA pathogenic variants in locally advanced, triple negative breast cancer treated with platinum-based neoadjuvant chemotherapy

BackgroundWhether germline BRCA (gBRCA) pathogenic variants (PV) affect prognosis of women with triple negative breast cancer (TNBC) and whether it has implications for treatment decisions in the neoadjuvant setting is unclear.MethodsThis is a retrospective two-center cohort study comprising all women with early stage TNBC who have completed genetic testing and were treated with neoadjuvant dose-dense doxorubicin and cyclophosphamide followed by paclitaxel and carboplatin. All eligible patients treated between 10.2014 and 3.2020 were included. Data on clinico-pathological, pathological response, overall survival (OS) and disease-free survival (DFS) were evaluated. Differences in clinico-pathological features and outcomes were analyzed according to gBRCA status.ResultsSixty-four women were included in the final analysis, of which 31 had gBRCA PV (gBRCA carriers) and 33 were gBRCA wild-type. Clinico-pathological characteristics were similar between both groups. The odds for pathological complete response (pCR) were significantly higher in gBRCA carriers (74.2%) compared to BRCA wild-type women (48.5%), p = 0.035. At a median follow-up of 30 months, gBRCA carriers had significantly favorable OS (HR = 8.64, 95% CI 1.08–69.21, p = 0.042). The difference in DFS did not reach statistical significance (HR = 7.4, 95% CI 0.91–60.27, p = 0.062). The favorable OS for gBRCA carriers remained significant in multivariate analysis (p = 0.029) and was noted regardless of pathological response (p = 0.018).ConclusionCompared to wild-type, gBRCA carriers with locally advanced TNBC treated with neoadjuvant chemotherapy containing carboplatin had a higher pCR rate and better outcomes. These results strengthen the contention that gBRCA status should be considered when tailoring treatment decisions in women with locally advanced TNBC.

Immunotherapy for Early-Stage Triple Negative Breast Cancer: Is Earlier Better?

In this narrative review, we discuss the optimal timing ofimmune checkpoint inhibitors (ICI) in early triple negative breast cancer (TNBC), the landscape of predictive biomarkers for the use ofimmunotherapy, and the mounting literature suggesting a benefit for an early use of ICI. TNBC is associated with a poor prognosis relative to other breast cancer subtypes, and until recently, the treatment of TNBC was limited to cytotoxic chemotherapy. In 2021, the immune-checkpoint inhibitor, pembrolizumab, was approved in combination with neoadjuvant chemotherapy for patients with high-risk early stage TNBC. This approval changed the treatment paradigm of early TNBC concomitantly raised several challenges in clinical practice, pertaining to patient selection, toxicity management, and post-neoadjuvant treatment, among others. The introduction of neoadjuvant chemoimmunotherapy has transformed the treatment landscape for early TNBC. However, several challenges, including patient selection, toxicity management, and the identification of predictive biomarkers, need to be addressed. Future research should focus on refining the timing and duration of immunotherapy, optimizing the chemotherapy partner, and exploring novel predictive biomarkers of response or toxicity.

Prognosis and Adjusting Factors in Elderly Patients With Triple-Negative Breast Cancer: Comparing With Young and Middle Age Groups

PurposeProper breast cancer screening and treatment should be considered in the elderly population; however, some tend to be less proactive. Our study aimed to investigate the impact of old age on treatment and prognosis in triple-negative breast cancer (TNBC). MethodThe study included patients with primary TNBC stage I-III diagnosed from 2002 to 2019 in single institution and retrospectively analyzed. We defined young (< 40 years), middle and old (> 70 years) groups. Clinicopathological factors, treatment, and prognosis were analyzed according to age group of TNBC patients. ResultTNBC patients aged 70 and above were 3.3 times more likely (P = .019) to have lymph node metastasis at the time of diagnosis compared to younger patients, but were found to be 0.24 times less likely to receive chemotherapy. (P = .003) Old TNBC patients have an expected likelihood 2.2 times higher of undergoing mastectomy rather than breast-conserving surgery. (P = .042) The 5-year prognosis is poorer in young and old group. (61%, 86%, and 65% in young, middle, and old groups). (P < .001). In subanalysis, old group of stages I and II received fewer chemotherapy compared to youngers (P < .05), but not in stage III. In Cox regression analysis, age and stage had significant impact on prognosis (hazard ratio 2-3), but treatment factors did not. However, in stratified analysis of adjuvant therapy and stage, prognosis of Old TNBC patients in stage II was improved when they underwent neo or adjuvant chemotherapy. ConclusionTNBC presents challenges in older patients, who receive less aggressive treatment and have poorer outcomes. The primary cause of poor prognosis in old TNBC patients is the high disease stage at diagnosis, underscoring the need for promotion and education on early screening. Additionally, it is suggested that a more proactive approach to adjuvant chemotherapy is necessary for stage II old TNBC patients.

A novel treatment to enhance survival for end stage triple negative breast cancer using repurposed veterinary anthelmintics combined with gut‑supporting/immune enhancing molecules.

Patients with end‑stage metastatic disease have limited treatment options and those diagnosed with triple negative breast cancer (Her2, Estrogen receptor, Progesterone receptor) have a poor prognosis. Using a triple negative mammary tumor model selected for brain metastasis (4T1Br4) in the mouse, treatment options that may increase survival when therapeutics are applied at post‑metastasis were assessed. Anti‑parasitic benzimidazoles (BZs) destabilize microtubules, inhibit metabolic pathways, reduce cell proliferation, and induce apoptosis in tumor cells. Co‑administration of two BZs was selected, oxfendazole (OFZ) and parbendazole (PBZ), shown to overcome resistance development in anthelmintic effects by imposing metabolic delay to assess if multiple BZ approach is also suitable to enhance anticancer effects. It has been previously reported that treatment of mammary tumor‑bearing mice at an early stage with chitin microparticles (CMPs) decreased tumor growth and metastases by enhancing both innate M1 macrophage and TH1 adaptive immune response. Oral administration of CMPs was previously revealed to affect the gut in intestinal inflammation. A combination BZ (OFZ/PBZ) and CMP treatment was tested to target tumor development and metastasis and effects were compared in response to monotherapies of the same compounds or to untreated mice. The results demonstrated increased survival, decreased tumor cell proliferation, decreased metastasis in lungs and brain, increased levels of fecal SCFAs butyric, acetic, propionic and valeric acids with increased butyric and propionic acid levels in brain biopsies in combination treated compared with untreated mice. At the primary tumor, SCFA receptor FFAR2 expression was increased in combination treatment compared with untreated mice, suggestive of a non‑invasive cancer phenotype. The superior cytotoxic effects of OFZ/PBZ were confirmed as opposed to single treatment with OFZ or PBZ using 3D spheroids generated from a human breast cancer cell line, MDA‑MB‑468. These data are compelling for treatment option possibility even at late stages of metastasized breast cancer.

Abstract C138: Barriers to screening and diagnostic testing among patients with a confirmed triple negative breast cancer (TNBC) diagnosis

Abstract Introduction Triple negative breast cancer (TNBC) is an aggressive form of breast cancer that disproportionately affects people of racial and ethnic minority groups. TNBC is associated with poorer prognosis and lower long-term survival rates versus other subtypes. Understanding access to routine services like mammography and genetic testing may reveal areas for process improvement and enable equitable healthcare delivery. The objective of this study is to assess how screening, diagnosis, and genetic testing were described by race using a physician survey and patient-chart review. Methods Data collection consisted of a 60-min physician survey and linked retrospective review of patients’ charts conducted June-July 2022. Participating oncologists across the US (34% Central; 19% Southeast; 18% Northeast; 21% West; 9% East Coast) were required to be board-certified, in practice 3-30 years post-residency, and managing ≥ 7 patients with TNBC in the past 3 years. Oncologists extracted patient-level data from 2-4 patient records for the chart review. Selection of charts oversampled patients on Medicaid, Black and Latina patients, and patients with later stage TNBC to allow for robust disparities analyses. Data collected included tests and diagnostic procedures performed, rationale for tests and procedures, and barriers experienced in accessing care. Results 101 oncologists (73% male; 62% community vs 39% academic setting) provided information on 283 patients with TNBC [99% female; median age=46 years; race= 42% Black, 31% Latina, 25% White, 2% Other]. Most first-time mammograms were performed due to identification of symptoms (68%) as compared to annual screening (28%) or family history (4%). White patients were more likely to have a first-time mammogram for annual screening (40%) compared to Black patients (22%). Black patients were more likely to have a first-time mammogram due to identification of symptoms (72%) compared to White patients (58%). Oncologists perceived that few (4%) of their patients experienced barriers to mammogram access, though they perceived higher rates of barriers among Black patients (6%) than Latina (4%) or White (3%) patients. They listed cost, scheduling, and access to clinics as the predominant barriers patients experienced. Oncologists perceived that most patients (77%) encounter difficulty in accessing genetic testing; this varied by race, with oncologists reporting that 93% of Black patients, 86% of Latina patients, and 50% of White patients encounter difficulty in accessing genetic testing. Conclusions This study described oncologists’ perceptions of screening and diagnostic testing among patients with a confirmed TNBC diagnosis. Reasons for first-time mammogram differed by race (routine screening vs family history vs symptomology); Black patients were less likely to have a first-time mammogram for annual screening and Black and Latina patients were more likely to experience difficulty in accessing genetic testing. These barriers could delay diagnosis and impact treatment decisions, exacerbating existing disparities. Citation Format: Langa Bakhuluma-Ncube, Emily Fox, Laura Okpala, Natalia Sadetsky, Matt O’Hara, Jennifer Parr. Barriers to screening and diagnostic testing among patients with a confirmed triple negative breast cancer (TNBC) diagnosis [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr C138.

MAP7D3, a novel prognostic marker for triple-negative breast cancer, drives cell invasiveness and cancer-initiating cell properties to promote metastatic progression

BackgroundPatients with triple-negative breast cancer (TNBC) tend to develop visceral metastasis within five years, making them the most challenging BC patients to treat. The MAP7 protein family is a group of microtubule-binding proteins with a well-known role in microtubule-related cell migration, but its role in metastasis-related properties of TNBC remains unclear.MethodsqRT-PCR and western blot were used to validate mRNA and protein expression of the MAP7 family in the isogenic pairs of TNBC cell lines with low and high metastasis potential. Functional characterization of MAP7D3 was carried out using cell-based and mouse models. The clinical association between MAP7D3 and TNBC was established using datasets in the public domain.ResultsMAP7D3 expression was consistently upregulated in the metastatic subline IV2 and 468-LN at both mRNA and protein levels. Knockdown of MAP7D3 inhibited the 3D colony-forming ability, cell migration, and invasion ability of IV2 and 468-LN, indicating its significant contribution to the metastasis phenotypes. Mechanistically, inhibition of MAP7D3 could significantly increase the sensitivity of metastatic TNBC cells to docetaxel and gemcitabine treatment by reducing the expression of proteins related to breast cancer-initiating cells (BCICs) and drug resistance, as well as suppressing the activity of Rac1. The animal study showed that the depletion of MAP7D3 drastically reduced TNBC tumor growth and impaired the metastatic capability of TNBC cells. Elevated expression of MAP7D3 was found in the metastatic lymph nodes and was significantly associated with advanced stage and higher grade TNBC. Moreover, MAP7D3 expression was significantly correlated with the TNBC population, and its high expression was significantly associated with lymph node metastasis and poor survival outcomes of patients with TNBC.ConclusionOur study indicates that targeting MAP7D3 could be a promising therapeutic strategy for addressing the progression of TNBC, and MAP7D3 may serve as a novel predictive biomarker for the survival outcomes of triple-negative breast cancer.

Predictive Roles of Baseline Stromal Tumor-Infiltrating Lymphocytes and Ki-67 in Pathologic Complete Response in an Early-Stage Triple-Negative Breast Cancer Prospective Trial

High stromal tumor-infiltrating lymphocytes (sTILs) are associated with improved pathologic complete response (pCR) in triple-negative breast cancer (TNBC). We hypothesize that integrating high sTILs and additional clinicopathologic features associated with pCR could enhance our ability to predict the group of patients on whom treatment de-escalation strategies could be tested. In this prospective early-stage TNBC neoadjuvant chemotherapy study, pretreatment biopsies from 408 patients were evaluated for their clinical and demographic features, as well as biomarkers including sTILs, Ki-67, PD-L1 and androgen receptor. Multivariate logistic regression models were developed to generate a computed response score to predict pCR. The pCR rate for the entire cohort was 41%. Recursive partitioning analysis identified ≥20% as the optimal cutoff for sTILs to denote 35% (143/408) of patients as having high sTILs, with a pCR rate of 59%, and 65% (265/408) of patients as having low sTILs, with a pCR rate of 31%. High Ki-67 (cutoff &gt; 35%) was identified as the only predictor of pCR in addition to sTILs in the training set. This finding was verified in the testing set, where the highest computed response score encompassing both high sTILa and high Ki-67 predicted a pCR rate of 65%. Integrating Ki67 and sTIL may refine the selection of early stage TNBC patients for neoadjuvant clinical trials evaluating de-escalation strategies.

Long non‑coding RNA PTCSC3 suppresses triple‑negative breast cancer by downregulating long non‑coding RNA MIR100HG.

Long non-coding RNA (lncRNA) PTCSC3 is characterized as a tumor suppressor in thyroid cancer and glioma. The present study aimed to investigate the role of PTCSC3 in triple-negative breast cancer (TNBC). A total of 82 patients with TNBC were enrolled in the present study. The results showed that PTCSC3 was downregulated, while lncRNA MIR100HG was upregulated in tumor tissues compared with that in adjacent non-cancerous tissues of patients with TNBC. The follow-up study showed that low expression levels of PTCSC3 and high expression levels of MIR100HG were closely associated with poor survival of patients with TNBC. The expression levels of MIR100HG were decreased with the clinic stages of TNBC, while the expression levels of MIR100HG showed the opposite trend. Correlation analysis showed that the expression levels of PTCSC3 and MIR100HG were significantly correlated in both tumor tissues and adjacent non-cancerous tissues. The overexpression of PTCSC3 inhibited the expression level of MIR100HG in TNBC cells, while the expression level of PTCSC3 was unaffected. Cell Counting Kit-8 and Annexin V-FITC Apoptosis flow cytometry assays showed that overexpression of PTCSC3 led to inhibition, while overexpression of MIR100HG led to the promotion of TNBC cells viability and inhibited apoptosis of TNBC cells. In addition, overexpression of MIR100HG attenuated the effects of PTCSC3 overexpression on cancer cell viability. However, the overexpression of PTCSC3 did not affect cancer cell migration and invasion. Western-blot analysis showed that PTCSC3 suppressed viability and promoted apoptosis of TNBC cells through the Hippo signaling pathway. Thus, the present study demonstrated that lncRNA PTCSC3 inhibits cancer cell viability and promotes cancer cell apoptosis in TNBC by downregulating MIR100HG.