Niinikoski L, Hukkinen K, Leidenius MHK, et al. - Patients undergoing breast-conserving surgery (BCS) using ROLL vs RSL were retrospectively studied for surgical margins, reoperation rates, and local recurrences. At Helsinki University Hospital, 744 consecutive patients with impalpable primary invasive breast cancer underwent BCS between 2010 and 2012; of these, 318 patients underwent ROLL and 426 patients underwent RSL. Outcomes revealed comparable reoperation rates and local recurrence-free survival for ROLL and RSL in patients with impalpable breast cancer treated with BCS. Multifocality of the tumor, extensive intraductal component, larger tumor size, and smaller specimen weight, were identified as the risk factors for reoperations.