A2AR-phospho-STAT1 (Y701)-HLA-E axis as a potential immune modulatory pathway in radiotherapy-resistant triple negative breast cancer.

Introduction: Triple-negative breast cancer (TNBC), an aggressive form of breast cancer (BC) that is associated with poor prognosis, accounts for 10-15% of all BCs. Chemotherapy remains the standard of care (SOC) for advanced disease, with limited clinical benefit. Oncology clinical trials (CTs) are globally recommended and encouraged as the preferred treatment (tx) option for any cancer patient (pt). ‘TrialJectory’ (TJ) is an artificial intelligence (AI)-based technology that matches pts to oncology CTs. Here, we identified distinct characteristics of TNBC pts who signed up to the TJ platform compared to non-TNBC pts. Methods: Using AI and an unsupervised natural language processing approach, the TJ platform clinically matches pts to CTs. Matching is achieved by pt response to an online dynamic questionnaire (www.trialjectory.com) that collects detailed clinical data including clinico-pathologic characteristics, tx history, general health, and comorbidities. Those are compared to the eligibility criteria of available CTs to yield a high-quality actionable matched-trial list. Results: Between 1/2020 and 12/2021, out of 9796 BC pts that signed up, 2688 were TNBC pts (27%). There was no significant difference in age at sign-up between TNBC and non-TNBC patients (median age of 57 years vs 58 years, respectively). Consistently with Non-hispanic black (NHB) race prevalence in the different molecular subtypes in the general US population, NHB race had higher signup rate in TNBC compared to non-TNBC (9.95% vs 5.76%, respectively). TNBC pts signed up at a later disease stage compared to non-TNBC pts (19% of TNBC reported having a stage 1 disease compared to 27% of non-TNBC pts, p< 0.001).A significantly higher percentage of pts with advanced/metastatic TNBC signed up to the TJ platform before starting tx compared to non-TNBC patients (34% vs 22%, respectively, p< 0.001). Furthermore, there was a significant difference in the willingness to travel any distance within the US for a matched clinical trial between TNBC and non-TNBC pts (39% vs 34%, respectively, p< 0.001). Conclusions: In this study, we found significant differences in the characteristics of TNBC vs non-TNBC pts that have signed up to the TJ platform. There was an up to 2-fold enrichment of TNBC on the TJ platform pts compared to their frequency in the general population. While previous studies do not show a difference in stage distribution between different subtypes, TNBC patients initiated their search for CTs at a higher stage. In addition, advanced TNBC patients started their search earlier in their journey, before starting chemotherapy. This may reflect the lack of effective SOC and possibly, the motivation to avoid the use of chemotherapy. This is also supported by the willingness of TNBC patients to travel farther in order to identify and enroll in a CT compared to non-TNBC pts. Importantly, the motivation of TNBC pts to travel any distance has not been reduced despite the COVID-19 pandemic, reflecting a strong drive of this pt population to enroll in CTs. It also demonstrates that with the right access, diverse patient populations are willing to participate in clinical trials. In sum, TNBC pts are more likely to explore CT options, in the advanced stage setting, earlier in their journey. This study demonstrates the power of TJ platform for clinico-pathologic characterization and diverse pt groups, including their drivers and behavioral choices during their battle with cancer. Citation Format: Michal Safran, Yelena Lapidot, Tzvia Bader, Avital Gaziel. Triple Negative Breast Cancer (TNBC) patients are more likely to digitally explore clinical trial options and prior to receiving treatment for advanced disease compared to non-TNBC patients [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-13-05.

e13064 Background: Triple-Negative Breast cancer (TNBC) is a highly aggressive form of breast cancer, characterized by the lack of expression of Estrogen Receptor (ER), Progesterone Receptor (PR), and Human Epidermal Growth Factor-2 (HER-2). Patients with TNBC do not benefit from hormonal or Trastuzumab therapy due to the lack of appropriate targets for these drugs. The current retrospective multicentric hospital-based study at HCG, India, aims to analyze the available treatment paradigms in TNBC patients in real-world evidence. Methods: Data from 3180 female breast cancer patients was collected and compiled from various medical records department (MRD) and hospital database from three HCG centers. The data comprised demographic and clinicopathological details, treatment details and survival information. In addition, the clinical and pathological parameters and survival outcomes were compared between TNBC and non-TNBC patients. Results: About 22.92% (729/3180) patients had TNBC, and 77.08% (2451/3180) patients had designated as non-TNBC. In the TNBC subgroup, 22.36% (163/729) patients belonged to the younger age group (< 40 years), 65.98% (481/729) patients were in the 41-65 age group, while 11.66% (85/729) patients were > 65 years old. Whereas the age-wise distribution in the non-TNBC group was as follows: < 40 years- 15.46% (379/2451) patients, 41-65 years- 70.34% (1724/2451) patients, and > 65 years- 14.2% (348/2451) patients. In the present cohort, TNBC and non-TNBC groups' mean age was 51.06 ± 12.15 years and 53.29 ± 11.55 years, with no statistical significance. About 11.8% (86/729) of patients in the TNBC group and 10.4% (255/2451) of patients in the non-TNBC group opted for neo-adjuvant chemotherapy. About 32.37% of patients in TNBC and 37.45% of patients in the non-TNBC group underwent surgery. The 5-year OS was 68.58% and 83.41% for TNBC and non-TNBC patients, respectively, with a median 5-year survival of 2.13 years (95% CI 2.528-3.204) for TNBC patients whereas 5-year median survival of 2.096 (95% CI 1.36-4.368). The mean survival in TNBC patients < 40 years was 10.14 years, which was significantly lower when compared to patients in the 41-65 years (14.12 years) and > 65 years (19.45 years). Also, patients in the TNBC group who underwent surgery had a higher mean survival of 16.72 years than those who did not opt for surgery (14.49 years). Further, chemotherapy and radiotherapy also increased the life expectancy in patients in both the TNBC and non-TNBC groups. Conclusions: In the present study cohort, TNBC distribution in the at the HCG center in the Indian subcontinent is similar to that of the western population (23% in the US and the UK). Adjuvant chemotherapy and radiotherapy were significantly higher among TNBC cases than non-TNBC cases. Lack of patient consent or proper patient follow-up further reduces survival

Background: Breast cancer is currently the leading cause of cancer morbidity and mortality among Algerian women. To date, triple negative breast cancer (TNBC) shows substantial overlap with basal type cancer and it is associated with aggressive tumor behavior, poor prognosis and BRCA1 mutations. In the present study, we screened for the prevalence of BRCA1 and BRCA2 germline mutations in a cohort of 169 TNBC patients using PCR-Sanger sequencing and NGS with a cancer panel of 30 hereditary cancer genes or BRCA1/BRCA2 genetic test. Materials and Methods: 169 TNBC patients and their relatives were referred trough several public hospitals from six years (2013-2019). BRCA1 germline mutation was screened using PCR-Sanger sequencing in 66 TNBC patients with strong family history of breast and ovarian cancer and 103 sporadic TNBC patients including all exons where a mutation was previously found in Algerian population (exons 2, 3, 4, 10, 17 and 19). BRCA2 germline mutation was screened using PCR-Sanger sequencing in 24 TNBC patients with strong family history of breast cancer including all exons where a mutation was previously found in Algerian patients (exons 10 and 22). In addition, nine (9) TNBC patients with strong family history of breast and ovarian cancer were analyzed by NGS using BRCA1 and BRCA2 test or a cancer panel of 30 hereditary genes (Colors genomics). Results: The analysis of the genomic DNA samples of 169 TNBC patients revealed that 15 patients carried pathogenic germline variants in BRCA1 gene and three patients carried pathogenic variants in BRCA2 gene (10.65%). Eight distinct germline mutations in BRCA1 have been detected in this study: c.83_84delTG, c.181T>G, c.798_799delTT, c.505C>T, c.923_924delGC, c.2125_2126insA, c.5257A>G and deletion of exon 15. Interestingly, the recurrent and specific mutation c.83_84delTG has been detected in 4 unrelated TNBC patients. The pathogenic variant c.2125_2126insA has been detected in three unrelated families and also in the first relatives of 2 patients. The rare likely pathogenic variant BRCA1 c.5257A>G/p.Arg1753Gly has been detected in young female TNBC patient. The Del exon 15 in BRCA1 has been detected in two unrelated patients. Three distinct germline mutations in BRCA2 have been detected in three TNBC patients: c.1813dupA, c.7654dupA and c.8485C>T. Interestingly, these three mutations are reported for the first time in Algerian population. The c.1813dupA and c.8485C>T pathogenic variants have been detected in two young female TNBC patients with a family history of male breast cancer. Conclusions: In the current study, we detected recurrent germline mutations in BRCA1 gene in early onset TNBC patients. BRCA2 pathogenic variants have also been detected in young female TNBC patients. TNBC immunophenotype should be considered as an additional criterion for genetic counselling and testing of BRCA genes in Algerian women with early onset breast cancer. Citation Format: Farid Cherbal, Chiraz Mehemmai, Hadjer Gaceb, Hassen Mahfouf, Kada Boualga. BRCA1 and BRCA2 germline mutational spectrum in Algerian triple negative breast cancer (TNBC) patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1451.

3528 Background: Exosomes are well known by the "exosomal shuttle" that delivers oncogenic microRNAs (miRNAs), mRNAs, circular RNAs (circRNAs) and proteins to the recipient cells and tumor microenvironment, and may be used as promising biomarkers for disease diagnosis. This study aims to provide a theoretical basis to use stable exosomal circRNAs as new biomarkers for predicting the development, metastasis and therapeutic targets of TNBC. Methods: A strategy combining RNA-sequencing technique, bioinformatic analysis and RT-qPCR was used to determine the level of differential expressed circRNAs in serum exosomes samples (n = 43) from TNBC patients compared with non-TNBC patients. The expression of circHSDL2 were also detected in tumor tissues (n = 20) from TNBC patients and breast cancer cell lines by qRT-PCR. Cell cycle analysis, the wound healing assays and transwell assays were used to investigate the function of circHSDL2 in proliferation, invasion and metastasis of TNBC cells. FISH, dual-luciferase reporter and functional assays were performed to confirm the interaction between circHSDL2 and let-7a-2-3p in TNBC cells. Results: We profiled the circRNAs in the serum exosomes samples from TNBC patients and non-TNBC patients by RNA sequencing and detected 803 significantly differentially-expressed circRNAs. After bioinformatic analysis, circHSDL2 was chose to further study. RT-qPCR results showed that higher expression of circHSDL2 in TNBC cell lines and tumor tissues from TNBC patients. Moreover, overexpression of circHSDL2 promoted TNBC cells proliferation and invasion, while knockdown of circHSDL2 inhibited TNBC cells proliferation and invasion. Mechanistically, circHSDL2 acted as a "miRNAs sponge" to absorb let-7a-2-3p; let-7a-2-3p inhibited TNBC cell invasion and metastasis. Kaplan-Meier plots showed lower expression of let-7a-2-3p was connected to poor prognosis in TNBC metastasis patients from TCGA database. Conclusions: The expression of circHSDL2 was found significantly upregulated in serum exosomes and tumor tissues from TNBC patients. Moreover, circHSDL2 could promote cell proliferation, invasion and metastasis in TNBC cells. CircHSDL2 might be function as competing endogenous RNAs (ceRNAs) by targeting let-7a-2-3p in the progression of TNBC. Therefore, this study provides a fresh perspective on novel therapeutic targets and potential biomarkers for TNBC from exosomal circRNAs.

Background: triple-negative breast cancer (TNBC) is associated with hereditary and environmental risk factors plus an overall worse prognosis compared to other Breast Cancer (BC) subtypes. While TNBC risk factors, prevalence, clinical characteristics and prognosis may vary throughout different populations, limited data on Latin American patients forces clinical decisions to be based predominantly on data coming from non-Hispanic women. To obtain local epidemiological information, regarding risk factors and clinical outcomes, we analysed the largest Chilean BC registry. Methods: we conducted a retrospective population-cohort study involving females with any stage TNBC, treated at a community hospital (mid-low income) and at an academic private hospital (high income), between the years 2010 and 2021. Risk factors, reason for consultation, clinical and pathological characteristics and prognosis were separately analysed for both TNBC and non-TNBC subgroups. Univariate and multivariate analyses were performed to identify prognostic factors for survival on TNBC patients. Results: From 5,806 patients, 647 (11.2%) were identified as TNBC. Compared to non-TNBC patients, women were younger (median age 55.2 vs. 57.2, p=0.0001), with 15.8% of TNBC patients having been diagnosed before the age of 40 compared to 9.6% in non-TNBC (p= 0.0001). TNBC had a significantly lower screen-detected cancer rate (14.5% vs. 31.6% p= 0.0001) and worse stage at diagnosis. No differences were seen between patients seen at a community hospital and private centre, for both TNBC rate and stage. Other risk factors such as parity, age at first gestation, menarche, hormone therapy replacement and obesity showed no significant differences between TNBC and no-TNBC patients (table 1). With a median follow up of 57 months, 5-year overall survival (OS) and BC specific death were significantly shorter for TNBC compared to non-TNBC (76.4% vs 88.1% and 78.9% vs 91.2%, respectively; p=0.0001) (table 2). In the multivariate analysis, TN subtype (HR=2.3, p=0.0001), stage (HR=2.05 for stage II vs stage I, HR=7.04 for stage III vs. stage I, p=0.0001), lower income (HR= 1.64, p=0.0001), and non-screened detected BC (HR=1.32, p=0.03) were all associated with worse overall survival (table 3). Conclusion: This is the first study focusing on TNBC characteristics in Chilean BC patients and to our knowledge, the largest performed in a Latin American population. We identified a lower proportion of TNBC patients when compared with data reported from other LA groups and worldwide, a very low screen detected cancer rate and as expected significantly lower TNBC survival rate compared to non-TNBC women. While TNBC patients were younger compared to the non-TNBC group, this age difference was marginal compared to other reported studies. Community hospital patients (with mid-low income) were associated with lower survival rates for both all-cause mortality and BC specific survival, regardless of a similar stage distribution at diagnosis. Reflecting an underlying interaction between social and biological factors that needs to be addressed. Table 1. Patient characteristics: Triple-negative versus noN-triple negative breast cancer BMI: Body mass index; FH: Family history * Difference is statistically significant. Table 2. Survival comparison in triple-negative versus non-triple negative breast cancer * Difference is statistically significant. Table 3. Cox Regression Multivariate analysis * Difference is statistically significant. Citation Format: Benjamin Walbaum, FRANCISCO ACEVEDO, Catherine Bauerle, Mauricio Camus, Manuel Manzor, Raul Martinez, Paulina Veglia, Marisel Navarro, Constanza Guerra, Francisco Dominguez, Tomas Merino, Lidia Medina, CÉSAR SÁNCHEZ. Real-world data of clinical characteristics, risk factors and outcomes of Chilean triple-negative breast cancer patients [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-03-19.

Background:Triple-negative breast cancer (TNBC),defined by the absence of estrogen receptor (ER), progesterone receptor (PR),and human epidermal growth factor receptor 2 (HER2) expression, accounts for 12% to 20% of all breast cancers.Its prevalence differs between races.TNBC shows substantial overlap with basal-type and BRCA1-related breast cancers and it is associated with early recurrence of disease and poor outcome.In the current study, we sought to compare some clinical and tumor characteristics of breast cancer patients with or without TNBC. We also screened for the prevalence of germline BRCA1 mutations in TNBC patients. Materials and Methods: Clinical and tumor characteristics data of 3403 breast cancer patients were collected from cancer registries of anticancer center of Blida, public hospital of Oued Amizour, anticancer center of Batna and public hospital of Rouiba. Breast cancers were diagnosed between 2007 and 2014. All histopathologic and immunohistochemical diagnoses were reviewed by pathologists. Patients were divided in two groups: those with TNBC and those with other breast cancer subtypes. Differences between the two groups with regard to clinicopathologic parameters: age at diagnosis, menopausal status, histological grade and histological type, were examined using Chi-square test. BRCA1 was screened by PCR-direct sequencing in 56 TNBC patients (26 with a family history of breast cancer and 30 sporadic cases) including all exons where a mutation was previously found in Algerian population (exons 2, 3, 5, 11). Results: The median age at diagnosis for TNBC and non-TNBC patients was 46.96 years and 49.01 years, respectively.The overall prevalence of TNBC was 21.65% (737/3403). Our data showed significant differences in the distribution of age at diagnosis (P<0.0005) and tumor histological grade (P<0.0001) between TNBC and non-TNBC patients.Among tumor with histological grade III,TNBC accounted for 50.54% for all TNBC patients and non-TNBC accounted for 25.28% for all non-TNBC patients.Premenopausal women accounted for 60.71% and 58.9% for all TNBC patients and all non-TNBC patients, respectively. Our data analysis revealed no difference in the distribution of histological tumor type between the two groups.Two BRCA1 mutations, c.83_84delTG and c.2125_2126insA have been detected in two young TNBC patients with a family history of breast cancer. Interestingly, the mutation c.2125_2126insA has been detected in 4 relatives of TNBC proband.Conclusions:This largest Algerian population-based study showed that the prevalence of TNBC in Algerian women is similar to that in African-American patients and higher than reported in white women in Europe and America. The high prevalence of TNBC in Algerian women compared to western countries could be linked to environmental factors and genetic background. Further research is needed to determine long term survival rates in the two groups of breast cancer patients. Citation Format: Farid Cherbal, Hadjer Gaceb, Chiraz Mehemmai, Insaf Saiah, Rabah Bakour, Abdelhalim Ould-Rouis, Tarek Touahria, Hassen Mahfouf, Samia Daoudi, Wassila Benbrahim, Kada Boualga. Triple-negative breast cancer in Algerian population: clinicopathological and molecular study. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5284. doi:10.1158/1538-7445.AM2015-5284

BackgroundIn recent years, breast cancer has been classified on the basis of estrogen or progesterone receptor (ER/PR) status and whether the human epidermal growth factor 2 receptor (HER2/neu) protein is overexpressed. Based on this system, breast cancer is broadly divided into the triple negative breast cancer (TNBC) and the non-TNBC subtypes. TNBC is a subtype of breast cancer, notable for its propensity to metastasize early and display a comparatively more aggressive course than its non-TNBC counterpart. Certain clinico-pathologic and demographic risk factors have been associated with breast cancer. In this study, we aim to compare mean age, ethnicity, family history, tobacco use and stage at presentation between TNBC and non-TNBC subtypes at our inner city university program.MethodsWe reviewed data in our tumor registry between January 2000 and December 2005 with particular attention to mean age, race, family history, tobacco use and stage at presentation. We found a total of 445 patients with various subtypes of breast cancers. We included only those patients in whom the status of both ER/PR and the status of Her2/neu protein overexpression were recorded. Our strict selection criteria lead to an exclusion of about 103 patients. Out of the remaining 342 patients, 39 were TNBC and 303 were non-TNBC.ResultsMean age of onset for TNBC vs. non-TNBC patients was 59.87 ± 15.67 years vs. 60.09 ± 13.98 years respectively (P = 0.9272). In terms of ethnicity, TNBC vs. non-TNBC patients had the following racial backgrounds: black, 58.97% vs. 39.27%; white, 35.90% vs. 57.76%; Chinese, 2.56% vs. 0.99%; others, 2.57% vs. 1.98% respectively (P = 0.004, OR = 2.755). Comparisons with respect to a history of tobacco abuse for TNBC vs. non-TNBC patients revealed a positive smoking history in 20.51% vs. 27.72% whereas there was no former or current smoking history in 71.79% vs. 61.72% respectively (P = 0.4385). Comparison of family history of a breast cancer in TNBC vs. non-TNBC patients showed that positive family history of breast cancer was seen in 30.77% vs. 33.33%, no family history of cancer was seen in 51.28% vs. 51.82% and unknown 17.95% vs. 14.85% (P = 0.8384). Pathologic stage at the time of diagnosis for TNBC vs. non-TNBC patients was as follows: stage 0, 15.79% vs. 11.37% (P = 0.4332); stage 1, 34.21% vs. 30.98% (P = 0.6890); stage 2, 28.98% vs. 37.25% (P = 0.3205); stage 3, 18.42% vs. 17.25% (P = 0.0.8591); and stage 4, 3.63% vs. 3.14% (P = 0.8651). Analysis using Chi-square test revealed χ2 value of 0.855.ConclusionOur results add to the growing body of evidence pertaining to the association of certain demographic and clinico-pathologic characteristics in women with breast cancer. We found that in our patient population, there is a significant ethnic predisposition for the two types of breast cancers that we studied. African Americans were more likely to have TNBC compared to the higher frequency of non-TNBC in white females. We did not find a significant difference in mean age, cigarette smoking, family history and stage at diagnosis between the TNBC and non-TNBC breast cancer patients. These findings are all consistent with the previously published research studies.

Background: Triple negative breast cancer (TNBC) is characterized by the lack of expression of the genes for estrogen receptor, progesterone receptor or human epidermal growth factor recepter-2 and therefore it has a shorter recurrence-free interval. We compared the survival rates, health care costs and utilization of breast cancer recurrent patients who have triple negative versus no triple negative breast cancer. Methods: Analyses were conducted using Impact Intelligence Oncology Management (IIOM) (2002-2009) linked with United Health administrative claims. Patients were followed from the time of initial breast cancer diagnosis until death, disenrollment or end of the observation period. Continuous enrollment was required during the observation period. Staging and estrogen and progesterone receptors (ER/PR) and HER2 status were obtained at time of initial diagnosis. Patients’ age, region, cancer stage, and comorbid conditions were controlled for risk-adjusted comparison. A stratified log-rank test was used to determine the equality of survival functions. Cox regression was used for the risk-adjusted survival analysis. Health care resource use during the follow-up period after recurrence was modeled with negative binomial regression. Inverse probability weight adjusted generalized linear models were used to estimate risk-adjusted total health care costs. Results: The study included 289 recurrent breast cancer patients, out of which 87 (30%) had triple negative breast cancer. At time of recurrence, TNBC patients had similar age, plan, region, and cancer stage distribution relative to non-TNBC patients. During follow-up, TNBC patients had significantly lower survival rate (log-rank test P<0.001). After controlling for baseline differences, the overall mortality risk rates for TNBC recurrent patients were almost three times higher than non-TNBC recurrent patients (HR:2.84, p=0.056). The risk-adjusted annual number of hospitalizations was also higher for TNBC patients with a recurrent event (1.65 vs. 1.13, p=0.05). There were no differences in health care costs after recurrence between TNBC and non-TNBC patients. Conclusion: Although similar in health care costs, triple negative breast cancer is associated with higher mortality and number of hospitalizations after the recurrence of breast cancer. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-09-07.

Here, we investigated the possible predictive value of stromal caveolin-1 (Cav-1) as a candidate biomarker for clinical outcome in triple negative (TN) breast cancer patients. A cohort of 85 TN breast cancer patients was available, with the necessary annotation and nearly 12 years of follow-up data. Our primary outcome of interest in this study was overall survival. Interestingly, TN patients with high-levels of stromal Cav-1, had a good clinical outcome, with >50% of the patients remaining alive during the follow-up period. In contrast, the median survival for TN patients with moderate stromal Cav-1 staining was 33.5 months. Similarly, the median survival for TN patients with absent stromal Cav-1 staining was 25.7 months. A comparison of 5-year survival rates yields a similar pattern. TN patients with high stromal Cav-1 had a good 5-year survival rate, with 75.5% of the patients remaining alive. In contrast, TN patients with moderate or absent stromal Cav-1 levels had progressively worse 5-year survival rates, with 40% and 9.4% of the patients remaining alive. In contrast, in a parallel analysis, the levels of tumor epithelial Cav-1 had no prognostic significance. As such, the prognostic value of Cav-1 immunostaining in TN breast cancer patients is compartment-specific, and selective for an absence of Cav-1 staining in the stromal fibroblast compartment. A recursive-partitioning algorithm was used to assess which factors are most predictive of overall survival in TN breast cancer patients. In this analysis, we included tumor size, histologic grade, whether the patient received surgery, radiotherapy or chemotherapy, CK5/6, EGFR, p53 and Ki67 status, as well as the stromal Cav-1 score. This analysis indicated that stromal Cav-1 expression was the most important prognostic factor for overall survival in TN breast cancer. Virtually identical results were obtained with CK5/6 (+) and/or EGFR (+) TN breast cancer cases, demonstrating that a loss of stromal Cav-1 is also a strong prognostic factor for basal-like breast cancers. Our current findings may have important implications for the close monitoring and treatment stratification of TN and basal-like breast cancer patients.

Chemoresistance and metastasis are the main causes of death in triple negative breast cancer (TNBC) patients and have been linked to a subpopulation of cancer stem cells (CSCs) with self-renewal and tumor-initiating properties. We have previously demonstrated that nitric oxide synthase (NOS) promotes tumor relapse and metastasis through modulation of CSC self-renewal properties. Importantly, NOS inhibition with the pan-NOS inhibitor NG-monmethyl-L-arginine (L-NMMA) reduced tumor growth and CSC renewal and tumor-initiating capacity and improved chemosensitivity to docetaxel in mouse models of TNBC. Based on these findings, we are conducting an ongoing Phase Ib trial of proprietary L-NMMA plus docetaxel in refractory locally advanced or metastatic TNBC (NCT02834403). The primary endpoint will be the maximum tolerated dose (MTD) of the L-NMMA and docetaxel combination. The study will be conducted in two stages. Stage 1 will determine the MTD of L-NMMA when combined with 75 mg/m2 docetaxel, and stage 2 will determine the MTD of L-NMMA when combined with 60 mg/m2 docetaxel. Five dose levels of L-NMMA (5, 7.5, 10, 12.5, and 15 mg/kg) will be investigated in stage 1, with 7.5 mg/kg as the starting dose. In stage 2, the starting dose of L-NMMA will be one dose level above the MTD determined in stage 1. As patients are accrued in both stages, a standard Bayesian model averaging continual reassessment method approach will be used to determine L-NMMA escalation/de-escalation. L-NMMA (Days 1−5 of each cycle) and docetaxel (Day 1 of each cycle) will be administered for six 21-day cycles. The major inclusion criteria will be female patients with pathologically advanced (progressive disease or refractory to 3 cycles of standard chemotherapy) or metastatic (any line) TNBC, Eastern Cooperative Oncology Group performance status of ≤2, life expectancy ≥6 months, and adequate organ function. Major exclusion criteria include any cardiac history and pregnancy/breastfeeding. Correlative studies will include evaluation of the pharmacokinetics and pharmacodynamics of the L-NMMA and docetaxel combination and tissue and blood-based markers of treatment response. Notably, analysis of RPL39 and MLF2 in plasma cell-free DNA samples will be performed. We have previously identified these genes as part of a chemotherapy resistance signature derived from breast cancer patient biopsies and have found that they promote breast CSC self-renewal, treatment resistance, and lung metastasis through NOS upregulation. Study enrollment began in August 2016. Two patients have been enrolled; both patients received 7.5 mg/kg L-NMMA and 75 mg/m2 docetaxel and no dose-limiting toxicities have been observed to date. L-NMMA Plus Docetaxel for refractory TNBC Citation Format: Jenny Chang, Angel Rodriguez, Joe Ensor. Clinical phase Ib trial of L-NMMA plus docetaxel in the treatment of refractory locally advanced or metastatic triple negative breast cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT037. doi:10.1158/1538-7445.AM2017-CT037

Purpose: Based on clinical and molecular data, breast cancer is a heterogeneous disease. Breast cancers that have no expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) are defined as triple negative breast cancers (TNBCs); luminal cancers have different expressions of ER, PR and/or HER2. TNBCs are frequently linked with advanced disease, poor prognosis and occurrence in young African women, and about 15% of the cases are associated with germline BRCA1/2 mutations. Since radiotherapy is utilized as a principle treatment in the management of TNBC, we aimed to investigate the chromosomal instability and radiosensitivity of lymphocytes in TNBC patients compared to luminal breast cancer patients and healthy controls using the micronucleus (MN) assay. The effect of mutations in breast cancer susceptibility genes on chromosomal radiosensitivity was also evaluated.Methods: Chromosomal radiosensitivity was evaluated in the G0 (83 patients and 90 controls) and S/G2 (34 patients and 17 controls) phase of the cell cycle by exposing blood samples from all patients and controls to 2 and 4 Gy ionizing radiation (IR).Results: In the G0 MN assay, the combined cohort of all breast cancer, TNBC and luminal patients’ exhibit significantly elevated spontaneous MN values compared to controls indicating chromosomal instability. Chromosomal radiosensitivity is also significantly elevated in the combined cohort of all breast cancer patients compared to controls. The TNBC patients, however, do not exhibit enhanced chromosomal radiosensitivity. Similarly, in the S/G2 phase, 76% of TNBC patients do not show enhanced chromosomal radiosensitivity compared to the controls. In both the G0 and S/G2 phase, luminal breast cancer patients demonstrate a shift toward chromosomal radiosensitivity compared to TNBC patients and controls.Conclusions: The observations of the MN assay suggest increased chromosomal instability and chromosomal radiosensitivity in South African breast cancer patients. However, in TNBC patients, the irradiated MN values are not elevated. Our results suggest that the healthy lymphocytes in TNBC patients could handle higher doses of IR.

BackgroundThe aim of the present study was to investigate whether the androgen receptor (AR) status affects the efficacy of neoadjuvant chemotherapy (NACT) in triple negative breast cancer (TNBC) patients, and to elucidate the predictive biomarkers and mutations associated with pathological complete response (pCR) in AR-positive TNBC patients.MethodsThe current retrospective cohort included 226 TNBC patients who underwent NACT. AR and FOXC1 were assessed by immunohistochemistry on pretreatment biopsy specimens of 226 TNBC patients from 2018 to 2022. The clinicopathological features of AR-negative, AR < 10%, and AR ≥ 10% TNBC patients were analyzed to confirm the appropriate threshold. The response was evaluated in terms of pCR and Miller-Payne (MP) grade in the subsequent mastectomy or breast conservation samples. Next-generation sequencing (NGS) was utilized to further investigate the molecular characteristics of 44 AR-positive TNBC patients.ResultsAmong the 226 TNBC patients, compared with AR-negative and AR < 10% tumors (68.58%, 155/226), AR ≥ 10% TNBC patients (31.41%, 71/226) exhibited distinct clinicopathological features, while no significant difference was detected between those with AR-negative tumors and those with AR < 10% tumors. Thus, tumors with AR ≥ 10% expression were defined as having AR positive expression. The pCR rate of AR-positive TNBCs was lower than that of AR-negative TNBC patients (12.68% vs. 34.19%, p < 0.001). In TNBC, multivariate analysis demonstrated that FOXC1 was an independent predictor of pCR (p = 0.042), whereas AR was not. The pCR rate was higher in FOXC1 positive patients than in FOXC1 negative patients (34.44% vs. 3.13%, p < 0.001). In the AR-positive TNBC subgroup, patients with FOXC1 expression had lower AR expression, higher Ki-67 expression, and higher histological grade. Compared with AR-positive TNBC patients who achieved pCR, the non-pCR patients had a greater percentage of mutations in genes involved in the PI3K/AKT/mTOR pathway.ConclusionsThe current study indicated that the AR-positive TNBC is correlated with lower rates of pCR after NACT. The expression of FOXC1 in TNBC patients and AR-positive TNBC patients could be utilized as a predictive marker for the efficacy of NACT. The present study provides a rationale for treating these non-pCR AR-positive TNBC tumors with PI3K/AKT/mTOR inhibitors.

Introduction: There is a critical need to develop biomarkers of response and resistance to adjuvant chemotherapy for TNBC. In preliminary studies, homologous recombination deficiency (HRD)-causing alterations have been reported in TNBC patients. HRD may impact response to standard chemotherapy as well as investigational therapies, such as PARP inhibitors and platinum agents. We report on the prognostic impact of two such markers in a large cohort of early stage TNBC patients who were uniformly treated with adjuvant doxorubicin (A) and cyclophosphamide (C). Aims: To investigate BRCA1 promoter methylation (PM) and HRD score as prognostic markers in TNBC patients treated with adjuvant AC on S9313. Methods: SWOG protocol S9313 accrued 3,125 women with early stage breast cancer to two alternative dose schedules of AC with no difference in outcomes between the two arms (J Clin Oncol 2007). We identified 425 (14%) patients with centrally determined TNBC status for whom tissue was available. BRCA1 PM (methylation specific PCR) and HRD score (composite of loss of heterozygosity, telomeric allelic imbalance and large-scale state transitions, Myriad Genetics Inc.) were performed on genomic DNA isolated from pre-treatment FFPE breast tumor tissue. HRD was classified as positive if there was either a deleterious tumor(t) BRCA1 or BRCA2 mutation and/or a pre-defined HRD score &amp;gt; 42. The markers were tested for prognostic effect on DFS and OS using a Cox regression model with adjustment for randomized treatment assignment. Results: For 425 TNBC patients median age was 45 years (range 22-74) and at a median follow up of 10.2 years there are 166 DFS and 129 OS events (5 year DFS and OS = 74% and 82%, respectively; 10-year DFS and OS = 66% and 73%). BRCA1 PM was determined in 82% (348/425) and was detected in 32% of patients. Presence of BRCA1 PM was suggestive of better DFS, but not statistically significant (HR=0.74; 95% CI 0.50-1.08, p=0.12). HRD results were determined in 91% (379/425) and 67% were HRD positive (27% with tBRCA mutation and 40% tBRCA negative but HRD score &amp;gt;42). HRD positive status was associated with a better DFS (HR = 0.69; 95% CI 0.49-0.96 (p=0.027)) and OS (HR= 0.67; 95% CI 0.47-0.97 (p=0.032)). High HRD score (≥42) in tBRCA negative patients (n=274) was also associated with better DFS (HR = 0.62; 95% CI 0.42-0.92). tBRCA status (positive versus negative) did not impact DFS (p = 0.78). Conclusions: Two thirds of TNBC patients receiving adjuvant AC chemotherapy had tumor HRD positivity. HRD was associated with better DFS and OS, perhaps due to high responses to AC. HRD status has the potential to be used as a selection criterion to identify TNBC patients who receive significant benefit from anthracycline chemotherapy, and may also be of value in selecting patients suitable for treatment with other DNA damaging agents like platinum salts/PARP-inhibitors. Citation Format: Priyanka Sharma, William Barlow, Andrew K. Godwin, Harsh Pathak, Kamilla Isakova, Anne R. Hartman, Kristen M. Timms, Hannah M. Linden, Debu Tripathy, Gabriel N. Hortobagyi, Daniel F. Hayes. Impact of homologous recombination deficiency (HRD) biomarkers on outcomes in triple-negative breast cancer (TNBC) patients treated with AC chemotherapy (SWOG S9313) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1776. doi:10.1158/1538-7445.AM2017-1776

Outcomes of Immediate Breast Reconstruction in Triple Negative Breast Cancer: A Propensity Score-Matched Analysis

Triple-negative breast cancer (TNBC) is associated with aggressive tumor behavior, poor prognosis and BRCA1 mutations. There are limited data regarding TNBC among Algerian women. In this study, we sought to determine clinical and tumor characteristics associated with TNBC. We also screened for the prevalence of BRCA1 mutations in unselected cohort of TNBC patients. Clinical and tumor characteristics data of 877 breast cancer patients diagnosed between 2011 and 2015, were collected from cancer registry of public hospital of Rouiba. Patients were divided in two groups: those with TNBC and those with other breast cancer subtypes. Differences between the two groups with regard to clinical and tumor characteristics were compared using Fisher's exact test. BRCA1 mutations analysis was performed in unselected cohort of 103 women with TNBC, including all exons where a mutation was previously found in Algerian population (exons 2, 3, 5, 11). The median age at diagnosis for TNBC and non-TNBC patients was 47.4years and 49.4years, respectively. The proportion of TNBC was 19.95%. Our data showed significant differences in menopausal status, TNM stage, histological type, tumor histological grade, Ki67 expression and family history of breast cancer between TNBC and non-TNBC patients. Four distinct deleterious mutations in BRCA1 gene were detected in eight young TNBC patients. TNBC is associated with young age, poor histopathological characteristics and family history of breast cancer. BRCA1 mutations have been detected in young TNBC patients. TNBC phenotype should be added as criterion to screen for BRCA1 mutations in Algerian women.