Abstract P3-13-12: The margin of breast-conserving surgery when ductal carcinoma in situ is present within invasive ductal carcinoma

Abstract

Abstract Objective: The presence of ductal carcinoma in situ (DCIS) in invasive ductal carcinoma (IDC) may increase the rates of positive margins and re-excision. Literature addressing this association is limited. This study aimed to explore the factors that are associated with positive margins and re-excision, as well as to evaluate the influence of positive margins on the survival of patients with breast cancer containing both invasive and in situ ductal carcinoma. Methods: A retrospective medical chart review of patients diagnosed with DCIS within IDC who underwent BCS at the Revlon/UCLA Breast Center between January 2003 and December 2008 was performed. Results: Of the 488 eligible patients, 267 patients (53.9%) underwent re-excision. The presence of residual disease upon re-excision was the highest in patients who initially had positive margins involved by both DCIS and IDC. In multivariate analysis, calcifications, tumor size, positive lymph nodes, and the presence of extensive intraductal component (EIC) were significantly associated with initial positive margins, with the latter having the highest hazard ratio (HR, 5.5–5.7, P = 0.000). Tumor size, molecular subtype, and final margin status were associated with disease-free survival. The final margin and regional lymph node status are significant prognosticators for breast cancer-specific survival. Conclusions: In patients with ductal carcinoma of the breast containing both invasive and in situ components, the rate of initial positive margin after BCS was high and was significantly associated with calcifications, tumor size, regional lymph node status, and the presence of EIC. Citation Format: Chen J, Ro A, Tan Q-W, Wang Z, Chang HR. The margin of breast-conserving surgery when ductal carcinoma in situ is present within invasive ductal carcinoma [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-13-12.