Abstract PO5-23-06: Predictive Factors for Reconstructive Method and Outcomes in Mutation-Positive Breast Cancer Patients

Abstract Background: BRCA1 and BRCA2 mutations significantly increase the risk of breast cancer, and prophylactic mastectomy reduces the risk by around 90% in these patients. Previous studies have explored predictors of mastectomy type in high-risk genetic mutation patients, but further characterization is needed. This study aims to identify factors associated with resection and reconstruction methods and predictors of postoperative complications in mutation-positive (M+) patients. Methods: A multicenter retrospective cohort study included patients with a genetic predisposition for breast cancer undergoing breast surgery, seen between January 2016 and October 2022. Patient demographics, comorbidities, oncologic history, operative details, and postoperative outcomes were collected. Descriptive statistics and multivariate logistic regression were performed. Results: Among the 176 patients analyzed, 75 (42.6%) had BRCA1, 71 (40.3%) had BRCA2, 11 (6.3%) had PALB2, and 8 (4.5%) had CHEK2 mutations. Mean age and body mass index (BMI) were 41.0±17 years and 24.9±6.9 kg/m2, respectively. Among patients with prior breast reconstruction (n=86, 48.9%), augmentation mammoplasty (n=31, 17.6%) was the most common procedure, followed by oncologic resection (n=21, 11.9%) and reduction mammoplasty (n=15, 8.5%). Nipple-sparing mastectomy (NSM) (n=107, 60.8%) was the most frequent surgical approach, followed by skin-sparing mastectomy (SSM) (n=43, 24.4%), simple mastectomy (n=14, 8.0%), lumpectomy (n=4, 2.3%), and radical mastectomy (n=4, 2.3%). Tissue expander (n=77, 43.8%) was the most common reconstruction method. By a median follow-up duration of 23.9 months, 66 (37.5%) of patients experienced postsurgical complications. Operative complications recorded within 30 days included seroma (n=9, 5.1%), hematoma (n=8, 4.5%), cellulitis (n=10, 5.7%), dehiscence (n=13, 7.4%), surgical site infection (n=11, 6.3%), and delayed wound healing (DWH) (n=24, 13.6%). Other long-term complications included mastectomy flap necrosis (n=22, 12.5%), total reconstructive failure (n=9, 5.1%), red breast syndrome (n=2, 1.1%), and capsular contracture (n=12, 6.8%). The choice of autologous breast reconstruction was correlated with younger age (OR 0.81, 95% CI: 0.69-0.95, p = 0.012) and Hispanic or Latino race (OR 0.01, 95% CI: 0.001-0.25, p=0.007). BMI was significantly correlated with incidence of hematoma (OR 1.17, 95% CI: 1.02-1.33, p=0.024), DWH (OR=1.1, 95% CI: 1.01-1.20, p=0.030), and dehiscence (OR 1.25, 95% CI: 1.09-1.43, p=0.001). Choice of autologous reconstruction was positively correlated with DWH (OR 8.86, 95% CI: 2.25-34.86, p=0.002) and dehiscence (OR 18.24, 95% CI: 2.58-129.158, p=0.004). Conclusion: In this macroscopic study, the most common breast reconstruction method for M+ patients was tissue expander-based. However, only autologous reconstruction was found to have positive correlates, specifically younger age and Hispanic or Latino origin. Younger patients may pursue this method given less concern for short term complications, which are historically increased in autologous reconstruction. Minority distrust of foreign medical material implantation may play a role in Hispanic or Latino choice. Additionally, autologous reconstruction and BMI were associated with certain postoperative complications, particularly dehiscence, DWH, and hematoma, results consistent with general breast cancer surgery cohorts. This study helps better characterize the M+ population and contributes insight into the resection and reconstructive choice in this patient population. Citation Format: Shrayus Sortur, Jaytin Gupta, Christian Lava, Lauren Berger, Varsha Harish, Zoya Khan, Daisy Spoer, Lindy Rosal, Ian Greenwalt, Lucy De La Cruz, David Song, Kenneth Fan. Predictive Factors for Reconstructive Method and Outcomes in Mutation-Positive Breast Cancer Patients abstract. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-23-06.