Is Sentinel Lymph Node Dissection Necessary in All Patients with Ductal Carcinoma In Situ Undergoing Total Mastectomy?

When ductal carcinoma in situ (DCIS) is found on core needle biopsy, rates of upgrade to invasive cancer of 25 per cent and nodal positivity of 10 per cent have been reported. Sentinel lymph node dissection (SLND) is recommended when mastectomy is performed for DCIS. We investigated the role of SLND in DCIS patients undergoing partial and total mastectomy (TM). During the study period 2004 to 2013, 170 patients with DCIS were identified with a median age of 60 years (range 26-84 years). Of these, 58.2 per cent had partial mastectomy (PM) alone, 10.6 per cent had PM with SLND, and 31.1 per cent had TM with or without contralateral prophylactic mastectomy with SLND. Overall, SLND identified positive nodes in 4.2 per cent of patients. Upgrade to invasive carcinoma on final breast pathology was found in 8.2 per cent of patients overall, including 4.0 per cent of patients undergoing PM alone, 22.2 per cent undergoing PM with SLND, and 11.3 per cent for TM with SLND (P = 0.8). In this study, patients diagnosed with DCIS on core needle biopsy had lower than expected rates of positive sentinel nodes and upgrade to invasive carcinoma. Surgeons and patients should revisit the necessity of SLND in DCIS patients undergoing mastectomy, which could lead to decreased health expenditure, resources, time, morbidity, and emotional impact on patients.