No Ink on Ductal Carcinoma in Situ: A Single Centre Experience

Abstract Introduction: The incidence of ductal carcinoma in situ (DCIS) of the breast has greatly increased thanks to the widespread use of screening mammography. The primary aim of surgery is to prevent local recurrence by achieving a clear margin of resection although its extent still represents a controversial issue. Hence, a retrospective analysis of patients undergoing surgery for DCIS was performed in order to assess the association of margin widths of < 1 mm, 1 to 2 mm, and > 2 mm with ipsilateral breast tumor recurrence (IBTR) considering also the potential role of host-, tumor- and treatment-related factors. Methods: From 2000 to 2016, 388 patients diagnosed with pure DICS undergoing BCS with or without post-operative RT at the Breast Unit of “Ospedale Policlinico San Martino” in Genoa were selected. The pathologic analysis was always performed according to a standardized protocol including the measure of the microscopic distance to the nearest radial margin: positive margins were those with DCIS present at the inked margin; close margins were considered to have tumor between 0.1 to 0.9 mm, or 1 to 1.9 mm, and negative margins were > 2 mm. Results: At a median follow-up of 90 months there were 26 IBTR (10 invasive and 16 DCIS). In univariate analysis there was a significant difference in IBTR by comparing positive versus close/negative margins of excision (P = 0.05) and the number of re-operations (P = 0.000). On multivariate analysis, both the margin status (P = 0.002) and the number of re-operations (P < 0.001) were still significantly associated with IBTR. The actuarial IBTR rates were significantly different in patients with a positive margin of excision at the primary operation as compared to patients with close/negative margins (log-rank test, P = 0,042) while the stratification by the margin width (0.1-0.9 mm; 1.0-1.9 mm; > 2 mm) was not significant (log-rank test, P = 0,243). Conclusions: The policy of “no ink on the tumor” that is well accepted for invasive breast cancer can be translated to DCIS, because the actuarial IBTR rates were significantly different only in patients with a positive margin of excision as compared to patients with close/negative margins.