Abstract P3-18-16: Breast conserving surgery in BRCA-mutation carriers. A single Institution experience

Abstract BackgroundBRCA-mutation carriers have a lifetime risk of breast cancer (BC) that ranges from 36 to 70%. For patients (pts) without mutation, breast conserving surgery (BCS) (followed by radiation therapy) is the treatment of choice since it offers similar survival to that of unilateral mastectomy. However, the optimal local management in BRCA-mutation carriers remains a matter of debate and the role of bilateral salpingo-oophorectomy (BSO) in reducing BC risk might be influenced by age and medical BC treatments (such as GnRH analogues). Patients and methodsWe retrieved clinical pathologic characteristics of 124 BRCA-mutated BC pts, consecutively tested at our Institution from 2008 to 2018. Primary end-point was recurrence-free survival (RFS) evaluation in terms of disease-free survival (DFS), distant DFS (DDFS) and overall survival (OS). Secondary end-point was identification of independent predictive factors for BCS. Clinical pathologic characteristics were evaluated and compared using univariate and multivariate analysis. Kaplan-Mayer curves were used to describe DFS, DDFS and OS. ResultsMedian age at BC surgery was 41 years (range 24-74), most of the pts (79%) were pre-menopausal and presented with ductal invasive carcinoma (91.9%). As per biological subtype, 63 (50.8%) pts had luminal-like BC, 52 (41.9%) triple negative (TN) BC and 9 (7.3%) HER2 enriched-like BC. More than half pts (62.9%) presented with G3 tumors and median Ki-67 was 40% (range 5-95). 17 (13.7%) and 80 (64.5%) pts underwent neo-adjuvant and adjuvant chemotherapy, respectively; 64 (51.6%) pts received adjuvant endocrine therapy, 39 (31.5%) with the addition of GnRH analogue. When comparing BCS to mastectomy, regardless of BSO, we could not observe any statistically significant difference in all the RFS end-points. 10-year DFS rate was 56.4% and 79.5%, respectively (p=0.187); 10-year DDFS rate was 83.7% and 82.3%, respectively (p=0.689); 10-year OS rate was 87.7% and 85.1%, respectively (p=0.947). At a multivariate analysis, age ≤41 years (p=0.008; OR 0.309; 95% CI 0.190-0.513) and primary tumor dimension ≤21 mm (p=0.008; OR 0.320; 95% CI 0.114-0.426), were the only predictors of breast surgery type (BCS compared to any other surgical treatment). ConclusionsOur data suggest that young pre-menopausal BRCA-mutated pts with small tumors may not need up-front mastectomy and BSO might be postponed, when ovarian cancer risk epidemiologically rises and potential reproductive desire is fulfilled. Citation Format: Agnese Losurdo, Damiano Gentile, Monica Zuradelli, Andrea Sagona, Erika Barbieri, Monica Barile, Paolo Bianchi, Rosalba Torrisi, Wolfgang Gatzemeier, Marta Scorsetti, Corrado Tinterri, Armando Santoro. Breast conserving surgery in BRCA-mutation carriers. A single Institution experience [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-18-16.