What should be the width of radiological margin to optimize resection of non-palpable invasive or in situ ductal carcinoma?

Purposethe aim of our study was to investigate whether there is radiological margin that optimize resection of non-palpable invasive or in situ ductal carcinoma.Materials and methodsData were collected for all patients undergoing wire localization prior to therapeutic surgical excision between January 2010 and December 2013 at our institution. A 5 and 10-mm radiological margins were considered adequate for invasive ductal carcinoma (IDC) and in situ ductal carcinoma (DCIS) respectively. Clear histological margins were defined as no ink on the tumor for IDC and ≥2 mm for DCIS. Data were analyzed both in order to assess accuracy of the technique and in order to determine what radiological threshold should be taken.ResultsThree hundred seventy seven women were included to the study. The radiological thresholds permitted negative histological margins in 94.7%, 60.9% and 80.9% in the pure invasive ductal carcinoma group (IDC, n = 133), the pure ductal carcinoma in situ group (DCIS, n = 92) and the mixed group (both IDC and DCIS, n = 152) respectively. In an ROC analysis evaluating the ability of radiological thresholds to obtain free pathological margins: the AUC was 0.79 (0.71–0.87, 95% confident interval, p = .0007) for Pure IDC group, 0.67 (0.57–0.87, 95% confident interval, p = .0005) for pure DCIS group, and 0.72 (0.62–0.80, 95% confident interval, p < .0001) for the mixed group.ConclusionWe found that a radiological margin of 10 mm is needed in presence of an in situ component and 5-mm radiological margin seems enough in case of pure IDC tumors.