Operable Breast Cancer Research Articles

The efficacy of primary progesterone on survival in early breast cancer: A real world scenario.

e12522 Background: Surgery performed during progestogenic milieu improves survival in breast cancer patients. We previously proved efficacy of pre-operative progesterone in high-risk, operable breast cancer. In another multicenter randomized trial, intra-operative peri-tumoral local anesthetic injection showed 29% reduction in mortality. In this study, several patients had also received progesterone injection since this is adopted as standard of care across some centers including ours. We assessed the effectiveness of pre-operative progesterone in patients who were randomized in the local anesthetic study. Methods: We analyzed 1583 patients randomized on the local anesthetic study during December 2011-October 2018 with respect to receipt of progesterone. All patient who had breast lump of ≥2cm and/or node positive were eligible to receive progesterone injection before surgery. Kaplan Meier curves were plotted along with Cox regression analysis to study factors affecting disease-free and overall survival. Results: Of 1583, 454 patients did not receive, and 1129 patients received progesterone before surgery. The median age of whole cohort was 51 years, median pT size was 3 cm, 45% were node positive, 60% ER/PR+ and 24%TNBC. At median follow-up of 68 (0·5-72) months in surviving patients, there were a total of 292 DFS events (progesterone arm-193, no-progesterone arm-99). The 5-year disease-free survival (DFS) was 86.5% in the progesterone arm and 79.2% in the no-progesterone arm (HR-0.57,0.45-0.73, P<0.001). The 5-year overall survival (OS) was 90.5% in the progesterone arm and 82.8% in the no-progesterone arm (HR-0.47,0.36-0.63,P<0.001). On Cox Regression analysis (Table), administration of progesterone injection was an independent prognostic factor for DFS (HR-0.53,0-41-0.70, p<0.001) and OS (HR-0.44,0-32-0.60, p<0.001) both. Conclusions: The receipt of pre-operative progesterone improved outcomes in the setting of another randomized trial. It should be administered to all high risk (T2/N1) breast cancer patients who are planned for surgery first. [Table: see text]

Interpectoral nodal dissection for invasive breast cancer: A retrospective single institution study from India.

e12585 Background: Interpectoral lymph nodes are one of the axillary lymphatic drainage sites in breast carcinoma. Usually dissection of Interpectoral nodes (IPN) avoided during axillary dissection as they are not the primary lymphatic drainage site. Our study aims to identify the rate of positivity of Interpectoral nodes in invasive breast cancer, predictors of IPN positivity in relation to tumour location, size, grade and hormone receptor status and to evaluate the need for IPN clearance during axillary dissection. Methods: A retrospective analysis of histopathology reports of 367 patients who underwent Axillary dissection in a single centre from Jan 2017-Dec 2022 for breast cancer was analysed. Inclusion criteria: Female Patients with operable Invasive Breast cancer with node positive axilla who underwent axillary dissection (upfront and post chemotherapy). Exclusion criteria: metastatic breast cancer, node-negative patients/sentinel lymph node biopsy, inadequate nodal dissection, and incomplete clinicopathological information. Data was analysed looking for presence of nodes in interpectoral tissue in Axillary dissection and to identify the positivity of interpectoral lymph nodes in specimens. Results: Interpectoral nodal dissection was done in n=216 of the 367 patients. The clinicopathological characters are described in Table. IPN were identified in 35% (n=77) of the 216 Axillary dissection specimens. IPN were positive in 7.8% (17 of 216) of patients who had interpectoral nodal dissection. 22% of the interpectoral lymph nodes removed were positive. As regards tumour size, Rotter's nodes were identified commonly in T3 and T4 tumours and positive in people with N2 and N3 disease. By multivariate analysis, T stage and N stage were the most important determinants of IPN yield and positivity. Site of tumour, neoadjuvant therapy, molecular subtype or Ki 67 were not found to be associated with either presence or positivity of interpectoral nodes. In 5 cases IPN positivity upstaged the nodal stage and in 1 patient it was the only positive node. Conclusions: As IPN is positive in most LABC, whenever axillary dissection is done in such cases Interpectoral nodes can be safely removed while dissecting level III nodes. Nodal recurrence is the most common site of recurrence post mastectomy and hence Interpectoral nodes need to be routinely removed in patients undergoing Axillary dissection for operable breast cancer to enable accurate staging and to prevent local or systemic failure. [Table: see text]

Outcomes of the Electrothermal Bipolar Vessel Sealing Device and Electrocautery in Modified Radical Mastectomy Patients.

Introduction With the rising trends in breast cancer throughout the world, the traditional modus of intraoperative tissue dissection using a scalpel, scissors, or electrocautery needs to be re-evaluated in the wake of newer modalities, such as electrothermal bipolar vessel sealing (EBVS) devices, which may theoretically reduce the postoperative complications and morbidity in these patients. Aimand objective The objective of this study is to compare an EBVS device to electrocautery (diathermy) in modified radical mastectomy (MRM), based on selected intraoperative and postoperative outcomes. Study procedure This was a comparative cross-sectional section study that included 60 patients with operable breast cancer (stages I and II, TNM classification, and post-neoadjuvant stage III disease). Patients were divided into two groups for surgery: one group underwent an MRM using the EBVS device (Group A), while the other group had the procedure performed using conventional electrocautery (Group B), as per the surgeon's choice depending on theatre slot and equipment availability. Intraoperatively, the total operative time, time for raising the flaps, time taken for breast tissue dissection, time for axillary dissection, and blood loss were recorded. Postoperative parameters included total drainage volume, number of days of drainage, seroma formation, and other complications. Patients were followed up for one month after surgery, with early postoperative complications such as wound infection, upper limb lymphedema, seroma, flap necrosis, and nerve injuries being documented. Results The groups were found to be comparable in terms of the age distribution, TNM staging, stage grouping, and nodal status of the patients. The EBVS device group demonstrated statistically significant advantages in total operative time, axillary dissection time, flap raising time, breast tissue dissection time, intraoperative blood loss, total drainage volume, and days of drainage. However, no statistically significant difference was found between the two devices in terms of seroma formation, early postoperative complications, and duration of postoperative stay at the hospital. Conclusion While the use of EBVS in MRM provides a considerable decrement in the total operative duration, duration of the various steps of surgery, intraoperative blood loss, and postoperative volume and duration of drainage, these devices do not offer an evident advantage in terms of the postoperative complications or morbidity.

Factors associated with delays in receipt of neoadjuvant chemotherapy in patients with operable breast cancer.

e13541 Background: Delays in neoadjuvant chemotherapy initiation (NACTI) after breast cancer (BC) diagnosis have been associated with worse outcomes. We evaluated incidence and predictors of delays of NACTI among high clinical risk patients treated with NACT on a national level. Methods: We conducted a retrospective cohort study using the National Cancer Database. Eligibility included age ≥18 years, diagnosis of non-metastatic BC between 1/1/2010 – 12/31/2020, who were treated with NACT within 180 days of diagnosis. Patients who received neoadjuvant endocrine therapy were excluded. Time to chemotherapy (TTC) in days was recorded. Patients were categorized into sub-cohorts by receptor status and clinical stage: 1) Hormone Receptor positive/HER-2 negative (HR+/HER2-) and were lymph node (LN) LN+; 2) HER-2 positive (HER2+) cT2+ or LN+; and 3) triple negative BC (TNBC) cT2+ or LN+. Multivariable logistic regression, adjusted for demographic, socioeconomic and tumor characteristics, was used to identify characteristics associated with delays > 60 days from diagnosis to NACTI. Multiple imputation was used for missing data. Results: We identified 145,697 eligible patients, 74% were White, 18% were Black, 3.3% were Asian, and 4.6% were Other/Unknown. Across all racial categories, 9.2% were Hispanic. Median age at diagnosis was 52 years (range 18-90), median TTC was 32 days (range 0-180), and 10% had a delay > 60 days. There were 40,345 patients in the HR+/HER2- cohort, 56,868 in the HER2+ cohort, and 48,484 in the TNBC cohort; 12%, 9.0%, and 8.9% (p <0.001) had a delay in NACTI, respectively. In multivariable analysis among the HR+/HER2- sub-cohort, characteristics associated with delays in NACTI included Black race (OR 1.71, 95%CI 1.57-1.86) and Hispanic ethnicity (OR 1.76, 95%CI 1.60-1.94) compared to White and non-Hispanic patients. Patients with Medicare, Medicaid, or who were uninsured were more likely to be delayed (OR 1.44 95%CI 1.30-1.58, 2.10, 95%CI 1.92-2.29, 2.28, 95%CI 1.99-2.61) compared to those with commercial insurance. Results were similar in the HER2+ and TNBC cohorts, as seen in Table. Conclusions: Among patients with operable BC who received NACT, patients who were Black, Hispanic, had Medicaid or no insurance had as high as a twofold increase in odds of a delay in NACTI. Targeted interventions to address these racial and socioeconomic disparities are necessary to ensure equitable care. Multivariable logistic regression adjusted for demographic, socioeconomic and tumor characteristics variables (n= 145,697). [Table: see text]

Trends and outcomes in patients receiving neoadjuvant chemotherapy for breast cancer in Ontario: A population-based study.

e12664 Background: Modern neoadjuvant chemotherapy (NAC) regimens in breast cancer offer higher rates of pathologic complete response, an ability to guide further adjuvant treatment, and may de-escalate surgery. However, the utilization of NAC has been heterogeneous in Ontario. This study aimed to describe trends in NAC use in Ontario, report survival outcomes, and explore factors associated with overall survival in these patients. Methods: This was a population-based cohort study using linked health administrative data in Ontario, Canada. From the Ontario Cancer Registry, we identified women ≥18 years who underwent neoadjuvant chemotherapy followed by surgery for operable (cT1N1, cT2-3N0, or cT2-3N1) breast cancer between 2012 and 2020. Patients were divided by receptor subtype (triple negative breast cancer [TNBC], ER+/HER2-, ER+/HER2+, ER-/HER2+) and characteristics were compared using standardized mean differences (SMDs). Five-year overall survival (OS) and breast cancer-specific survival (BCSS) were determined and reported for each subtype. Associations with OS and BCSS were calculated for patient and disease characteristics using univariate and multivariable Cox proportional hazards models and Fine and Gray models, respectively. Results: 3,804 women underwent NAC for cT1N1, cT2-3N0, or cT2-3N1 breast cancer in Ontario between 2012 and 2020. The largest contributing subtype was ER+/HER2- patients (39.3%) followed by those with HER2+ disease (ER-/HER2+ 13.8%, ER+/HER2+ 23.4%), and TNBC (23.5%). The median age was 50 years (IQR 42-59 years). Most patients were clinically node-positive (2,736; 71.9%), and underwent mastectomy (2,397; 63.0%). There was a significant increase in the number of patients receiving NAC in Ontario, from 217 in 2012 to 667 in 2019 ( p<0.001), with a greater increase among patients with TNBC or HER2+ disease. Compared to those with ER+/HER2- disease, TNBC patients were treated for smaller tumours (28.6% T3 vs. 39.8%; SMD = 0.24), and were more likely to be node-negative (39.1% N0 vs. 22.1%; SMD = 0.38). Similar trends for nodal status were found for patients with ER-/HER2+ (26.7% N0) and ER+/HER2+ cancer (27.9% N0). 5-year OS for the entire cohort was 88.1% (95% CI 87.1 – 89.2%). Survival was highest for ER+/HER2+ patients (94.2%, 95% CI 92.6 – 95.8%) and lowest for TNBC patients (80.1%, 95% CI 77.5 – 82.8%). Similar patterns were seen for BCSS. Factors associated with OS in a multivariable model included older age (increase in 5 years HR 1.1, 95% CI 1.07 – 1.14), N1 status (HR 1.99, 95% CI 1.61 – 2.47), larger tumour size (T3 HR 1.83, 95% CI 1.34 – 2.5), mastectomy (HR 1.45, 95% CI 1.2 – 1.75), and TNBC (versus ER+/HER2- HR 1.9, 95% CI 1.56 – 2.32). Conclusions: The use of NAC has increased in Ontario, particularly among TNBC and HER2+ patients. Women with TNBC have worse outcomes compared to those with ER+/HER2- disease, despite being treated for less advanced disease.

The Relationship Between Body Composition and Pathological Response to Neoadjuvant Chemotherapy in Breast Cancer Patients.

Background The pathological response rate in operable breast cancer (BC) patients receiving neoadjuvant chemotherapy (NAC) is postulated to be related to body composition. The success of complete pathological response (pCR) is a known prognostic factor in BC patients treated with NAC. We aimed to accurately measure body composition through BMI and skeletal muscle mass and observe their effects on pCR. Materials and methods Patients diagnosed with operable BC who had a positron emission tomography-computed tomography (PET-CT) or chest/abdominal CTtaken at the time of diagnosis were retrospectively screened and enrolled in this study. Muscle mass was defined by third lumbar vertebra (L3) level transverse CT images, and data, including weight and height, were collected from the chemotherapy records. All these data were evaluated together with the postoperative pathological results. Results Sixty-nine operable BC patients with a median age of 46 (range: 29-72) years were included in the study. In all patients, regardless of sarcopenia, 23% (n = 16) achieved pCR to NAC. The pCR rate was 37.5% (n=6) in sarcopenic patients and 62.5% (n=10) in non-sarcopenic patients (p = 0.530). Overweight (n=4; 25%) and obese (n=2; 12.5%) patients also had a lower pathological response than normal-weight (n=10; 62.5%) BC patients (p=0.261). Conclusion Both sarcopenia and obesity independently and synergistically contribute to poorer pathological responses after NAC. Addressing these conditions through tailored interventions, such as nutritional support, exercise programs, and careful monitoring of body composition, could improve treatment outcomes. Further research with larger patient populations and comprehensive body measurements is essential to fully understand these relationships and develop effective strategies to mitigate their impact.

Disparities in quality of life among patients with breast cancer based on surgical methods: a cross-sectional prospective study

To determine the impact of breast conservation on quality of life and identify treatment-related and other demographic factors associated with post-breast cancer treatment quality of life. A prospective study was conducted on 392 women who underwent breast cancer surgery at Hangzhou Cancer Hospital from January 1, 2013, to December 31, 2022. Operable breast cancer patients who had completed all treatments except endocrine therapy were included. Patients with tumor recurrence/metastasis, bilateral or male breast cancer, and other primary malignancies were excluded. After enrollment, patients were asked to complete the BREAST-Q scale, and their pathological and medical records were reviewed. Analysis of variance was used to compare the quality of life scores among the groups. Univariate and multivariate linear regression analyses were performed to identify independent factors associated with quality of life scores in different domains. Participants completed the BREAST-Q scale at a median of 4.6 years after surgery. Quality of life scores varied based on the therapeutic strategy. Breast conservation has significant advantages over mastectomy in terms of breast satisfaction, psychosocial, and sexual well-being. Compared to oncoplastic breast-conserving surgery, mastectomy was independently associated with decreased breast satisfaction, psychosocial, and sexual well-being, while conventional breast-conserving surgery showed comparable outcomes to oncoplastic breast-conserving surgery in terms of these factors. Breast conservation leads to an improvement in quality of life compared to mastectomy. Oncoplastic breast-conserving surgery does not lead to a decrease in quality of life compared to conventional breast-conserving surgery and offers better outcomes compared to mastectomy.

The prognostic value of preoperative neoindices consisting of lymphocytes, neutrophils and albumin (LANR) in operable breast cancer: a retrospective study.

Preoperative inflammatory factors and nutritional status are strongly associated with the prognosis of a variety of cancers. We explored the relationship between preoperative lymphocytes, neutrophils and albumin (LANR) and progression-free survival in breast cancer patients. The clinical and follow-up data of 200 breast cancer patients were retrospectively analyzed in this study, and the value of LANR was determined as follows: LANR, lymphocytes × albumin/neutrophils. ROC curves, COX proportional risk regression analysis and subgroup analysis were used to assess the prognostic value of LANR in progression-free survival of breast cancer patients. The median age of the patients was 55.5 years (range 50-62 years). The median follow-up time was 46 months (range 33-55 months). In progression-free survival, the area under the LANR curve was 0.748 and the HR (95% CI) was 0.035 (0.679-0.817). LANR was associated with age (p=0.02), positive axillary lymph nodes (p<0.001), TNM stage (p<0.001) and human epidermal growth factor receptor 2(p=0.004). The results indicated that preoperative LANR may be a reliable predictor of progression-free survival in patients with operable breast cancer. LANR may be an essential predictor for breast cancer patients and provides a therapeutic basis for clinicians and patients.

Abstract PO1-08-10: Impact of Oncologist-Led Genetic Counseling and Testing on Prophylactic Mastectomy Rates Among Multi-Ethnic Women with Operable Breast Cancer

Abstract Introduction: Approximately 5-10% of breast cancers are attributed to an inherited pathogenic variant (PV) in breast cancer predisposition genes, such as BRCA1 and BRCA2. Identifying women with hereditary breast cancer syndromes is critical to inform risk-appropriate screening and prevention strategies. For example, contralateral prophylactic mastectomy (CPM) has been shown to reduce the risk of new breast primaries without a demonstrated survival benefit. In a prior study, we found that women with pathogenic/likely pathogenic (P/LP) variants were over four times more likely to undergo CPM compared to those with benign/likely benign (B/LB) variants. In recent years due to expanded indications for genetic testing and social distancing during the COVID-19 pandemic, oncologist-led genetic testing and telehealth genetic counseling has gradually replaced in-person genetic counseling visits. We aimed to understand how changes in the delivery of genetic counseling and testing services impacted CPM rates among multi-ethnic women with operable breast cancer in the post COVID-19 period. Methods: We conducted a retrospective cohort study among 1,080 women diagnosed with unilateral breast cancer who underwent germline genetic testing between 2013 and 2022 at Columbia University Irving Medical Center (CUIMC) in New York, NY. The pre COVID-19 period was defined as 2013-2019 and the post COVID-19 period as 2020-2022. Demographics, including age, race/ethnicity and marital status, and clinical characteristics, such as year of diagnosis, breast cancer stage, tumor hormone receptor status, family history of breast cancer, and genetic test results, were extracted from the electronic health record (EHR). We used univariable and multivariable logistic regression analyses to estimate the odds ratio (OR) and 95% confidence interval (95% CI) associated with each variable and receipt of CPM. Results: Among 1080 evaluable women, mean age at diagnosis was 51.2 years old (SD, 12.3) with 39.6% non-Hispanic White, 27.8% Hispanic, 11.4% non-Hispanic Black, 9.0% Asian, and 12.2% multi-racial/other. Within the overall study population, 12.1% of women had P/LP variants and 21.4% had variants of unknown significance (VUS) results. Non-Hispanic Whites and Blacks had the highest frequency of P/LP variants, whereas VUS results were more common among Hispanics and Asians (see Table). Twenty-three percent of women in the study population underwent CPM. In multivariable analysis, younger age at diagnosis, more advanced stage breast cancer, family history of breast cancer, Hispanic race and P/LP results on germline genetic testing were associated with increased CPM rates. Hispanic women were over 60% more likely to undergo CPM compared to non-Hispanic White women (adjusted OR=1.63, 95% CI=1.07-2.47). No significant change in CPM rates was observed in the post-COVID era compared to the pre-COVID era. Conclusion: We aimed to understand how the transition to telehealth and oncologist-led genetic testing affected CPM rates. Although we did not observe a change in CPM rates in the post-COVID era, Hispanic women had significantly more VUS results and were over 60% more likely to undergo CPM compared to non-Hispanic White women. In future studies, we hope to improve risk communication of genetic test results and the risks and benefits of CPM, particularly in vulnerable and underserved populations. Table 1 Genetic testing results and rates of contralateral prophylactic mastectomy stratified by race/ethnicity in women diagnosed with operable breast cancer and undergoing germline genetic testing from 2013-2022 at Columbia University Irving Medical Center, New York, NY Citation Format: Alissa Michel, Kelly Luo, Vicky Ro, Matthew Fine, Meghna Trivedi, Wendy Chung, Roshni Rao, Tarsha Jones, Elana Levinson, Carrie Koval-Burt, Donna Russo, Ilana Chilton, Rita Kukafka, Katherine Crew. Impact of Oncologist-Led Genetic Counseling and Testing on Prophylactic Mastectomy Rates Among Multi-Ethnic Women with Operable 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 PO1-08-10.

Abstract PO5-15-03: Neutrophil-lymphocyte ratio and absolute lymphocyte count, inflammatory markers, may predict lymph node metastasis in elderly patients with operable breast cancer

Abstract Background: Blood-derived systemic inflammatory markers such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR) and absolute lymphocyte count (ALC) have been demonstrated as predictive markers of recurrence and prognosis in several malignancies. Increased chronic inflammation with aging has been reported to be involved in cancer cells and their microenvironment. Several studies have also reported a close relationship between inflammatory markers and cancer grade and prognosis in the elderly. In this study, we retrospectively examined the relationship between lymphocyte-related inflammatory markers and prognosis in elderly breast cancer patients. Method: We included 602 patients diagnosed with primary invasive breast cancer at 8 institutions between 2008 and 2013, all of whom were older than 70 years old and had undergone breast cancer surgery. Preoperative blood collection data were used to analyze the relationship between NLR, PLR, LMR, ALC and clinicopathological data including recurrence. Results: The pathological stages of the 602 patients were Stage I: 275, Stage II: 276, and Stage III: 51, with median NLR, PLR, LMR, and ALC values of 2.21, 134.51, 6.76, and 1840, respectively. The mean age of the patients was 75.3 years. The median follow-up was 72.8 months. 76 patients relapsed, and the mean time to relapse was 42.7 months. Lymphocyte-associated inflammatory markers and Li Sheng pathological characteristics showed no significant differences in stage, presence or absence of recurrence, or form of recurrence, but lymph node metastasis on surgical pathology showed significant differences between cases with and without lymph node metastasis in NLR and ALC (P&amp;lt; 0.05). Conclusions: LMR and ALC were considered useful biomarkers that can be easily measured to predict lymph node metastasis in operable elderly breast cancer Citation Format: Emi Tokuda, Midori Morita, Akihiko Shimomura, Yoshiya Horimoto, Yukino Kawamura, Yumiko Ishizuka, Katsutoshi Sekine, Sayaka Obayashi, Yuki Kojima, Toru Higuchi. Neutrophil-lymphocyte ratio and absolute lymphocyte count, inflammatory markers, may predict lymph node metastasis in elderly patients with operable 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 PO5-15-03.

Abstract PO3-01-04: Neoadjuvant compared to adjuvant chemotherapy combined with trastuzumab in patients with HER2-positive breast cancer: a register-based cohort study

Abstract Introduction Neoadjuvant therapy (NAT) is considered the standard of care in patients with HER2-positive breast cancer mainly due to the possibility to adjust the post-neoadjuvant treatment based on the tumor response to NAT. However, there is no convincing evidence on a survival benefit with NAT compared to adjuvant therapy (AT) for HER2-positive breast cancer. The aim of the present study was to compare the two therapeutic strategies in a register-based cohort of Swedish patients with primary operable HER2-positive breast cancer. Method The research database BCBaSe 3.0, which is based on the Swedish National Quality breast cancer register, was used to identify patients with primary operable HER2-positive breast cancer that diagnosed between 2008 and 2020 and received either NAT or AT including chemotherapy and trastuzumab. To mitigate confounding by indication bias, propensity score matching (PSM) with 1:1 matching was applied. The effectiveness of the two therapeutic strategies was investigated through analyzing distant disease-free survival (DDFS), breast-cancer specific survival (BCSS), and overall survival (OS). Multivariate Cox regression analyses were performed for the outcomes of interest to provide Hazard Ratios (HR) and corresponding 95% Confidence Intervals (CI). Results In total, 7258 patients with primary operable HER2-positive breast cancer treated with either NAT or AT were identified, 1789 (24.6%) received NAT and 5469 (75.4%) AT. After 1:1 PSM, 1258 patients in each therapeutic strategy were available for comparisons. After a median follow-up of 63 months, no statistically significant differences between NAT and AT were observed in either outcome (HR for DDFS: 0.97; 95% CI: 0.72 – 1.30; HR for BCSS: 0.69; 95% CI: 0.45 – 1.07; HR for OS: 0.72; 95% CI: 0.50 – 1.05). In subgroup analyses, estrogen-receptor status did not impact the results that remained statistically non-significant between NAT and AT whereas in patients with clinically positive lymph node status, NAT resulted in better BCSS (HR: 0.44; 95% CI: 0.22 – 0.89) and OS (HR: 0.49; 95% CI: 0.29 – 0.90). The latter trend was not evident in patients with clinically negative lymph node status. Conclusion Our study results confirm the equivalence of NAT and AT in terms of prognosis for patients with operable HER2-positive disease and imply a potential benefit of NAT compared to AT in patients with clinically positive lymph node status. Considering the emerging treatment strategies in HER2-positive breast cancer patients treated with NAT (pertuzumab as a part of NAT, T-DM1 as post-neoadjuvant therapy) that have been shown to improve survival but are not reflected in the study cohort, NAT should be considered as the strategy with the higher possibility to improve long-term prognosis for patients with HER2-positive disease. Citation Format: Servah Hosseini-Mellner, Åsa Wickberg, Antonis Valachis, Andreas Karakatsanis. Neoadjuvant compared to adjuvant chemotherapy combined with trastuzumab in patients with HER2-positive breast cancer: a register-based cohort study [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 PO3-01-04.

Abstract PO5-03-11: Ultra-low dose nivolumab added to dose-dense, cisplatin-based neoadjuvant chemotherapy in locally advanced, borderline operable triple negative breast cancer: A matched case-control study

Abstract Background In India, the majority of patients with triple negative breast cancer(TNBC) present with locally advanced and often inoperable disease due to lack of screening, awareness, and social stigma. This makes pathological complete response(pCR) after neoadjuvant chemotherapy(NAC) less likely, leading to early recurrence and poor survival outcomes. Immune checkpoint inhibitors(ICI) in addition to platinum agents have improved both pCR and disease-free survival(DFS). However, these are accessible only to a very small proportion(&amp;lt; 3%) of patients in LMICs due to exorbitant costs. The activity and cost-effectiveness of low dose ICI has been demonstrated in head and neck. The efficacy of low dose ICI in the neoadjuvant setting for TNBC has not been studied. We examined our outcomes with ultra-low dose nivolumab(&amp;lt; 0.6 mg/kg every 2 weeks) added to NAC for locally advanced and borderline operable TNBC. Methods A retrospective analysis of 132 patients with TNBC who received NAC with the ddDCEP regimen(Docetaxel 75mg/m2 and Cyclophosphamide 600 mg/m2 alternating with Epirubicin 90mg/m2 and Cisplatin 60mg/m2 every 2 weeks for 8 cycles) or ddDCEP plus low dose nivolumab(&amp;lt; 0.6mg/kg/2 weeks) and underwent mastectomy at our centre between 2018-2023 was carried out. 105 and 27 patients received ddDCEP alone and ddDCEP + low dose nivolumab respectively. Using rigorous exact matching, 26 matched pairs(52 patients) were obtained based on tumour grade and AJCC TNM stage. pCR in the surgical specimen was the principal outcome assessed. Survival data, adverse events and cost were also analysed. Results The median age of cases and controls was 42 and 40 years respectively. Tumour histology was ductal carcinoma most patients. Across both groups the stage distribution was the same with nearly 85% stage III(IA 3.8%;IIB 7.7%; IIIA 23.1%;IIIB 43.2%;IIIC 19.2%). 92% of cases and 85% of controls had node positive disease. 62% of cases and 46% of controls had T4 disease. At a median follow up of 9 months, there were no recurrences or deaths among the cases. The most common immune mediated adverse event was hypothyroidism seen in 11.5% of cases. The rates of grade 3/4 anaemia, thrombocytopenia and febrile neutropenia were approximately 38%, 10% and 3.8% across cases and controls respectively. The median dose of nivolumab was 0.27mg/kg/2weeks as opposed to the approved dose of 3mg/kg/2weeks for most indications. The range of doses varied from 0.07 to 0.58mg/kg/2weeks. In the overall cohort, the addition of nivolumab did not have any apparent effect on the pCR rates which were identical at 42.3% in both cases and controls. However, there was a positive correlation between the total dose of nivolumab/kg(body weight) and the likelihood of pCR(coefficient 0.34; p-value 0.046). Patients who received higher than the median dose of nivolumab had a significantly higher likelihood of attaining pCR than those who received lower doses (69.2% pCR vs.15.4%;p-value 0.015). The cost of nivolumab at 0.6 mg/kg for 4 doses is approximately USD2000 compared to USD34400 for 8 doses of pembrolizumab in the neoadjuvant component of the KEYNOTE-522 regimen. Conclusion In this cohort with locally advanced/inoperable TNBC, the addition of ultra-low dose nivolumab did not improve pCR overall compared to a matched control set who did not receive ICI. However, in the subset of patients who received between 0.27-0.58 mg/kg/2weeks, the pCR rates were significantly higher at 69%. This presents a promising and cost-effective approach for TNBC management in LMICs. This effect needs verification in larger phase II/III trials. Table. Citation Format: Zachariah Thomas, Josh Georgy, Ashish Singh, Anjana Joel, Divya Thumaty, Ajoy John, Jerryes Wisely, Grace Rebekah, Elanthenral Sigamani, Anish Cherian, Deepak Abraham, Paul Jacob, Rajesh Balakrishnan, Patricia Solomon, Selvamani Backianathan, Raju Chacko. Ultra-low dose nivolumab added to dose-dense, cisplatin-based neoadjuvant chemotherapy in locally advanced, borderline operable triple negative breast cancer: A matched case-control study [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 PO5-03-11.

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 PO3-11-11: Reproductive concerns of Japanese young women with breast cancer: a longitudinal study

Abstract Background: Treatment-related infertility is one of the major concerns of young women with breast cancer. We explored the longitudinal change and factors associated with reproductive concerns of Japanese young women in a prospective cohort study. Method: Women under the age of forty with newly diagnosed, histologically confirmed, operable breast cancer were recruited to “Hope for YBC Project” (UMIN000034481). The participants were asked to respond to anonymous self-written questionnaire regarding reproductive concern, anxiety and depression, perception of motherhood and socio-economic status at baseline and 6M. Result: Among 215 participants who were enrolled in the study, the mean age of 143 participants who responded to both the questionnaire at baseline and 6M was 35.7 (range 25-39): 78 (54.5%) had a university degree or higher, 104 (72.7%) had a partner, 65 (45.5%) had more than one child, and 84 (58.8%) had a household income more than 5 million yen. 57 (39.9%) had desire for having a baby, 37 (25.9%) were unsure and 43 (33.6%) were not interested. Among 143, 33 (23%) attempted fertility preservation. Baseline score of Reproductive Concerns After Cancer scale (RCAC) had weak correlation with the total scores of Hospital Anxiety and Depression Scale (HADS) (r=.397, p&amp;lt; .001) and Decision Conflict Scale (DCS) (r=.365, p&amp;lt; .001), respectively. Perceived “sufficient explanation of the risk of recurrence” and “sufficient explanation of the necessity and benefit of pharmacotherapy” were significantly associated with reduced DCS score at baseline (p&amp;lt; 0.001). The desire for having a baby changed in 15 women (10.5%) at 6M. Although both DCS and HADS significantly lowered at 6M, there was no difference between RCAC score at baseline and at 6M. RCAC score at 6M had correlation with RCAC(r=.793, p&amp;lt; .001), DCS(r=.439, p&amp;lt; .001), and HADS (r=.401, p&amp;lt; .001) scores at baseline. RCAC score at 6M was also associated with younger age (r=.311), non-existence of partner (p=.001), non-existence of child (p=.014), desire for having a baby (p&amp;lt; .001) at baseline, attempt of fertility preservation (p=.025) and not receiving endocrine treatment (p=.047). Conclusion: Reproductive concerns of young women remained throughout the treatment, and concerns at later treatment phase were associated with decision conflict and anxiety at diagnosis. These results shows that young women, especially those who have higher risk of having reproductive concern, need psychological and decision support at diagnosis, including thorough explanation of risk of recurrence and benefit of systemic treatment from oncologists. Citation Format: Chie Watanabe, Hiroko Bando, Akemi Kataoka, Mai Okazaki, Tadahiko Shien, Eriko Tokunaga, Takashi Kuwayama, Chikako Shimizu. Reproductive concerns of Japanese young women with breast cancer: a longitudinal study [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 PO3-11-11.

Abstract PO4-22-10: Prognostic impact of preoperative lymph node diagnostic tools for patients with suspicious node positive breast cancer

Abstract (Abstract) Recently, the SOUND trial demonstrated the feasibility for omission of sentinel lymph node biopsy (SNB) in cases with negative ultrasound (US)-guided fine-needle aspiration cytology (FNA) of suspicious lymph nodes (LNs). An important consideration for omission of SNB depends on a highly accurate assessment of preoperative staging for axillary LNs. (Purpose) The purpose of this study was to investigate the impact of preoperative diagnostic tools for axillary lymph nodes (LNs) staging of early breast cancer. (Materials and Methods) A total of 3088 consecutive patients with operable breast cancer were retrospectively identified at our institution between April 2013 and March 2020. Patients with suspicious axillary LN of breast cancer were assessed using preoperative US and computed tomography (CT), underwent FNA or core needle biopsy (CNB). The inclusion criteria for both FNA and CNB were a cortical thickness [3 mm or abnormal morphological characteristics. Patients with biopsy-proven metastasis underwent axillary lymph node dissection (ALND), and those with a negative FNA or CNB underwent SNB. If the SNB was positive, ALND was performed. Diagnostic accuracy for SNB was calculated for both FNA and CNB. In addition, the patients in this study were divided into two groups as follows: the cN0-FNA negative group (suspicious LN but negative FNA) and the cN0-CNB group (suspicious LN but negative CNB). Overall survival (OS)and invasive disease survival(iDFS) was estimated by using the Kaplan-Meier method and compared by using the log-rank test. (Results) A number of patients with negative or suspicious metastasis US/CT findings of LNs were 3187, with 963 undergoing FNA and 395 undergoing CNB for suspicious LNs. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 63, 99, 99, 73, and 81% in FNA, and 87, 100, 100, 91 and 95% in CNB, respectively. SNB was performed in 207 (cN0-CNB group) of 395 CNB and 581 (cN0-FNA group) of 963 FNA patients. Two hundred and seven patients from the cN0-CNB group (T1ab; 42, T1c; 72, T2;84, T3;9 patients) treated with SNB were compared to 581 from the cN0-FNA group (T1ab;86, T1c;193, T2;278, T3;24 patients) in terms of number of LN metastasis. A number of patients with micrometastases, 1,2,3 or more than 4 positive LNs were 5(2%),7(3%),3(1%)9,3(1%) and 0 (0%) in cN0-CNB group, and 23(4%),67(12%),26(4%),12(2%) and 29 (5%) in cN0-FNA group, respectively. The significant difference in 5ys iDFS and OS was observed between CNB group and FNA group (94.2% vs.91.4%, p =0.04 and 99% vs. 95%, p=0.004, respectively). Conclusions The preoperative diagnosis of axillary LNs was influenced by the diagnostic tool used. CNB is a reliable method for the preoperative diagnosis of LN metastasis. The prognosis of early breast cancer with clinically metastasis-negative lymph nodes diagnosed by CNB is better than that by FNA. Table. Number of positive lymph nodes cN0-FNA (%) cN0-CNB (%) Total 207 100 581 100 0 189 91 424 73 micrometastasis 5 2 23 4 1 7 3 67 12 2 3 1 26 4 3 3 1 12 2 4 more than 0 0 29 5 Citation Format: Rikiya Nakamura, Shouko Hayama, Rikiya Nakamura, Naohito Yamamoto. Prognostic impact of preoperative lymph node diagnostic tools for patients with suspicious node positive 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 PO4-22-10.

Abstract PO3-07-12: Effect of neoadjuvant chemotherapy on peritumoral edema in early stage breast cancer and its prognostic value

Abstract Objectives: We aimed to evaluate the effect of neoadjuvant chemotherapy (NAC) on peritumoral edema (PE) and its prognostic value in operable breast cancer. Materials &amp; Methods: This retrospective study included 128 cT1-4N0-3M0 breast cancer patients who underwent contrast-enhanced magnetic resonance imaging (MRI) of the breast before and after anthracycline- and/or taxane-based NAC, followed by curative surgery at our hospital, between 2006 and 2016. T2-weighted MRI revealed PE, and PE before NAC (pre-PE) and PE after NAC (residual PE) were evaluated. The correlation between the presence or absence of PE and relapse-free survival was evaluated using a log-rank test and multivariable Cox regression analysis. The risk of recurrence was stratified according to the residual cancer burden (RCB). Results: Pre-PE was observed in 64 out of 128 patients (50%). Among 64 patients with pre-PE-positive breast cancer, residual PE was observed in 21 (32.8%). In the log-rank test, breast cancer with residual PE had a poorer prognosis than breast cancer with PE that had disappeared (p &amp;lt; 0.0001). In the multivariable Cox regression analysis, residual PE was a significant factor of poor prognosis (RR, 20.5; 95% confidence interval, 5.3–108.2; p &amp;lt; 0.0001). Regarding RCB stratification, compared to patients with breast cancer with disappeared PE, those with breast cancer with residual PE exhibited significantly poor prognosis in class II and class III (p = 0.006, 0.02). Conclusion: In breast cancer with PE, residual PE after NAC is a significant factor related to poor prognosis. Effect of neoadjuvant chemotherapy on peritumoral edema in patients with breast cancer and its clinical significance XX XX Citation Format: Hideo Shigematsu, Mutsumi Fujimoto, Yoshie Kobayashi, Tomoyuki Yoshiyama, Noriaki Matsuura, Daisuke Komoto, Kazuya Kuraoka. Effect of neoadjuvant chemotherapy on peritumoral edema in early stage breast cancer and its prognostic value [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 PO3-07-12.

Abstract PO2-02-04: The Impact of Statins on Breast Cancer Specific Mortality in a Diverse Patient Population with Stage I-III Hormone Receptor Positive, HER2 Negative Breast Cancer

Abstract Hormone receptor-positive (HR+), HER2 negative (HER2−) breast cancer has a long-term risk of recurrence, compared with other breast cancer subtypes, which ultimately impacts mortality outcomes. Although adjuvant endocrine therapy plays an integral role in risk reduction, disparities persist—with Black women experiencing higher mortality rates compared to White women. Multiple studies have demonstrated that statin use can lead to a reduction in breast cancer mortality, but there is limited information in relation to the impact of statins among diverse patient populations in the United States. To assess whether statin use is associated with an improvement in breast cancer-specific mortality (BCSM), we conducted a large, observational study in women aged 66 and older diagnosed with Stage I–IIIC HR+, HER2- breast cancer between 2013 and 2017. We identified eligible women using the SEER-Medicare database and linked them to the BRIDGE (BReast cancer Investigation of Disparities in GEorgia) cohort, a survivorship cohort of the Georgia Cancer Registry. Patients needed to be continuously enrolled in Medicare Parts A, B, and D in the 12 months following a breast cancer diagnosis. We used Cox proportional hazards models to estimate the impact of statin use within 12 months of diagnosis on BCSM with adjustment for age, stage, and race using multivariable-adjusted hazard ratios (HRs). A total of 2483 participants were identified, and of those, 303 (12.2%) were statin users, 383 (15.4%) were non-Hispanic Black women, and 1564 (63%) resided in census tract with greater than or equal to 10% poverty levels at the time of diagnosis. Distribution of age, stage, and race were similar between statin and non-statin users. Of the statin users, 41/303 (13.5%) were non-Hispanic Black women. The majority of statin users were prescribed lipophilic statins alone (169; 55.8%), and atorvastatin was the most commonly prescribed statin. There was no association between statin use and BCSM (HR 1.09; 95% CI 0.62-1.90) in the multivariable-adjusted model. Although preliminary results suggest that there is no association between statin use and BCSM among women with Stage I–IIIC HR+, HER2− breast cancer, further analyses are planned to explore statin use as a time-varying exposure, which may provide additional insights into the potential relationship between statin use and BCSM. In addition, analyses examining potential heterogeneity by race, tumor and treatment characteristics, and comorbidities are forthcoming. Given the low cost and relative accessibility of statins, we anticipate these findings will inform the clinical management of women with operable breast cancer, increasing parity in outcomes and potentially narrowing race disparities. Citation Format: Ruth Sacks, Maya Bliss, Micah Streiff, Leah Moubadder, Maret Maliniak, Tsion Armidie, Lindsay Collin, Kevin Kalinsky, Lauren McCullough. The Impact of Statins on Breast Cancer Specific Mortality in a Diverse Patient Population with Stage I-III Hormone Receptor Positive, HER2 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 PO2-02-04.

Abstract PO1-27-05: De-escalated neoadjuvant weekly nab-paclitaxel with trastuzumab and pertuzumab in HER2-positive early breast cancer (HELEN-006):a randomized,phase 3 trial

Abstract Background: Chemotherapy de-escalation is currently under investigation as a treatment approach for HER2-positive early-stage breast cancer(EBC). We conducted a phase 3 clinical trial to evaluate the effectiveness of a weekly regimen of nab-paclitaxel monotherapy in combination with dual HER2 blockade for HER2-positive EBC. Methods: We conducted a multicenter, randomized, open-label Phase 3 trial at six hospitals in China. Eligible participants were women aged 18-70 with locally confirmed, HER2-positive, stage II-III, invasive, operable breast cancer and an Eastern Cooperative Oncology Group performance status of 0 or 1. Participants were randomly assigned (1:1) using central block randomization, with block sizes of four, stratified by hormone receptor status, tumor stage, and node status. They were assigned to receive either intravenous nab-paclitaxel (125mg/m2 on days 1, 8, and 15) for six 3-week cycles (group A), or intravenous docetaxel (75mg/m² on day 1) and carboplatin (area under the concentration-time curve 6mg/mL per min on day 1) for six 3-week cycles (group B). Both groups received concurrent trastuzumab (8mg/m2 loading dose, 6mg/m2 maintenance dose on day 1) and pertuzumab (intravenous 840mg loading dose, 420mg maintenance dose on day 1). The primary endpoint was the proportion of patients achieving a pathological complete response(pCR) in the breast and axilla (ypT0/is ypN0) as determined by a local pathologist after surgery, assessed using a modified intention-to-treat analysis. To test for non-inferiority, we used a closed test procedure, considering the nab-paclitaxel group non-inferior to the docetaxel plus carboplatin group if the lower 95% confidence interval(CI) for the odds ratio (OR) was above 0.802, which accounted for a 5.5% non-inferiority margin (10% of the 55% pCR rate for docetaxel plus carboplatin and dual HER2 blockade regimen). We planned to test for superiority only if the non-inferiority test was positive, using an alpha value of 0.05. Safety was assessed in all patients who received the study drug. The trial is registered with ClinicalTrials.gov, with the registration number NCT04547907. Findings: Between September 10, 2020, and March 1, 2023, we randomly assigned 689 women, of whom 669 started treatment (332 with nab-paclitaxel and 337 with docetaxel plus carboplatin). The nab-paclitaxel group had a higher proportion of patients achieving a pCR (220 [66.3%, 95% CI 61.2-71.4]) compared to the docetaxel plus carboplatin group (194 [57.6%, 52.3-62.9]). The OR for pCR was 1.448 (95% CI 1.058-1.981), indicating a statistically significant difference (unadjusted p=0.021). Overall, 228 (34.1%) patients were noted to have at least one grade 3 or 4 event, 100(30.1%) in the nab-paclitaxel group and 128 (38.0%) in the docetaxel plus carboplatin group (P=0·032). The most common grade 3 or 4 events overall were nausea (98[14.6%] of 669 patients), diarrhea (80 [12.0%]), and neuropathy (51 [7.6%]).However, no treatment-associated deaths were identified. Conclusions: In neoadjuvant treatment of HER2-positive EBC, 18 weeks of nab-paclitaxel monotherapy combined with dual HER2 blockade has shown significantly higher pCR rates and improved tolerability compared to the standard docetaxel plus carboplatin and dual HER2 blockade regimen. These findings could potentially reshape preferences for neoadjuvant therapy in HER2-positive EBC. Patient Characteristics pCR by clinical-pathological variables Abbreviation:Nab-PHP,nanoparticle albumin-bound paclitaxel plus trastuzumab and pertuzumab; TCbHP,docetaxel plus carboplatin ,trastuzumab and pertuzumab; HR,hormone receptor; IHC,immunohistochemistry. *estrogen and/or progesterone receptor positive is classified as hormone receptor positive;estrogen and progesterone receptor negative is classified as hormone receptor negative Adverse events Abbreviation:Nab-PHP,nanoparticle albumin-bound paclitaxel plus trastuzumab and pertuzumab; TCbHP,docetaxel plus carboplatin ,trastuzumab and pertuzumab;ALT,alanine aminotransferase;AST,aspartate transaminase. Citation Format: Zhenzhen Liu, Xiuchun Chen, Jianghua Qiao, Jiao Dechuang, Chengzheng Wang, Xianfu Sun, Zhenduo Lu, Lianfang Li, Chongjian Zhang, Min Yan, Ya Wei, Chen Bo, Yueqing Feng, Miao Deng, Mingde Ma. De-escalated neoadjuvant weekly nab-paclitaxel with trastuzumab and pertuzumab in HER2-positive early breast cancer (HELEN-006):a randomized,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 PO1-27-05.

Abstract PO1-16-09: Does T1c-2N0-1M0 triple negative breast cancer derive a benefit from neoadjuvant chemotherapy?

Abstract Objective: Although neoadjuvant chemotherapy (NCT) is a standard approach for operable triple negative breast cancer (TNBC), the potential risks brought by it should also be noticed. Is the expanding indication of NCT to T1cN0M0 population appropriate? We conducted an investigation to compare the long-term survival of small tumor TNBC between NCT and adjuvant chemotherapy (ACT). Methods: For this propensity-matched analysis, we used data from SEER database. We enrolled 1183 cases with NCT and 2550 cases with ACT who are AJCC clinical T1c-T2 N0-N1, diagnosed with TNBC, from 2016 to 2017. The propensity score matching was utilized to minimize baseline characteristics bias. Based on the Cox proportional hazard regression model, we calculated hazard ratios (HR) with 95% confidence intervals (CIs). Results: Multivariate analysis in matched patients showed that NCT had no significant survival benefit compared with ACT in T1c-2N0-1M0 TNBC patients. Stratified analyses by T stage and N stage demonstrated NCT mainly presented a survival advantage in patients with N1 stage. Further investigation found that NCT didn’t improve BCSS (HR=0.472; 95% CI: 0.135-1.647; p=0.239) and OS (HR=0.392; 95% CI: 0.147-1.047; p=0.062) for patients with T1cN0M0 TNBC; however, for patients with T2N1M0 TNBC, it was associated with improved OS (HR=1.951; 95% CI: 1.003-3.797; p=0.049). Conclusion: In our study, we did not find any profit brought by NCT in the stage I and stage IIa cohorts, but even more unfavorable outcomes appeared in the T1cN0M0 cohort. Therefore, whether the candidates of NCT should be extended to T1cN0M0 still need to be cautious. Treatment effect on breast cancer-specific survival (BCSS) and overall survival (OS) by subgroup. Citation Format: Jie Zhang, Yushuai Yu, Weiwei Chen, Wenfen Fu, Ruiliang Chen, Jialu Yi, Chuangui Song. Does T1c-2N0-1M0 triple negative breast cancer derive a benefit from 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 PO1-16-09.

Abstract PO3-19-08: A phase 2 randomized pre-operative,window of opportunity trial investigating the effect of elacestrant with/without triptorelin in premenopausal patients with HR+/HER2- breast cancer – SOLTI-2104-PremiÈRe trial

Abstract Background. Premenopausal women diagnosed with HR+/HER2- breast cancer (BC) often have a different biology and worse prognosis. The SOFT and TEXT studies demonstrated an increase diseasefree survival (DFS) with ovarian function suppression (OFS) plus tamoxifen or exemestane compared to tamoxifen alone. Of note, high-risk clinicopathologic features, adjuvant chemotherapy, or aged ≤35 years correlated with greater OFS benefit. However, adding OFS in this context has intrinsic issues as higher toxicity, which led to treatment discontinuation (20% in SOFT trial), and suboptimal OFS was found in around 25% of patients (pts) with exemestane plus monthly triptorelin (SOFT-EST sub-study). Thus, new effective ET options without OFS are needed for premenopausal patients (pts). Elacestrant is the first oral, non-steroidal, selective estrogen receptor degrader (SERD) to demonstrate improved efficacy to SOC treatments and specifically compared to fulvestrant in postmenopausal pts with HR+/HER2- metastatic BC at the phase III EMERALD trial. In menopausal patients with HR+/HER2- early BC, the window of opportunity SOLTI-1905 ELIPSE trial (NCT04797728), showed that elacestrant was associated with a 27.3% rate of Complete Cell Cycle Arrest (CCCA) and a statistically significant suppression of Ki-67. Among Luminal A tumors, the CCCA rate was 45% and the average decrease in Ki-67 was 64.6%, while no CCCA was reported and the suppression of Ki-67 was less pronounced (31.7%) in the Luminal B population. There is still a need for investigating elacestrant without OFS in the premenopausal scenario. We hypothesize that elacestrant as a single agent or in combination with triptorelin is an effective and safe treatment regimen in premenopausal pts with HR+/HER2-negative early BC capable of achieving an equivalent CCCA rate as a subrogate of effectiveness regardless the use of OFS Study design. PREMIERE is a parallel, non-comparative, two-arm, randomized 1:1, open-label, multicenter, exploratory study in premenopausal women with primary operable HR+/HER2-negative BC. The study aims to evaluate the biological effects of elacestrant with or without triptorelin. Participants must have histologically confirmed HR+ (≥ 10%) and HER2- operable early BC stage I to stage IIB &amp;gt;1 cm with a Ki-67 between 10-35%. The primary objective is to assess the ability of each treatment arm to induce CCCA determined by central assessment of Ki-67 (% Ki-67 ≤ 2.7%). No formal comparison between treatment arms is intended. Secondary objectives include evaluating the biological activity of elacestrant with or without OFS, antiproliferative activity, changes in gene expression including PAM50 subtype changes, and the effect of optimal vs suboptimal suppression on CCCA . Serum E2 and FSH levels will also be evaluated. Safety and tolerability will be assessed based on adverse events and clinical laboratory test results. Pts will undergo screening and randomization, with stratification by PAM50 subtype (Luminal A vs Non-luminal A). Treatment will be elacestrant 400 mg once daily or elacestrant 400 mg once daily plus triptorelin 3.75 mg days +1 and +29 for 30 (+7) days. Surgery or biopsy will be performed after treatment completion, and a post-surgery visit will mark the end of the active follow-up period. Patients will receive SOC treatment after surgery. 48 patients will be recruited in 9 sites within SOLTI Spanish network in 9 months period. This study is financially supported by Menarini-Stemline. Citation Format: Meritxell Bellet- Ezquerra, Cristina Hernando, Pablo Tolosa, Maria Vidal, Yolanda Fernández, Santiago González-Santiago, Pilar Sanchez, Susana De La Cruz, Vanesa Ortega, Xavier Gonzalez-Farré, Milana Bergamino, Alejandra Espinosa, Tomás Pascual. A phase 2 randomized pre-operative,window of opportunity trial investigating the effect of elacestrant with/without triptorelin in premenopausal patients with HR+/HER2- breast cancer – SOLTI-2104-PremiÈRe 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 PO3-19-08.