Predictors of positive margins after local excision of ductal carcinoma insitu

Background: This study aimed to examine the association between clinicopath ologic parameters and positive margins in women with ductal carcinoma in si tu (DCIS) treated by breast-conserving surgery (BCS). Methods: We retrospectively reviewed the clinical, radiologic, and patholog ic data of 100 women who had undergone BCS for DCIS in our center. Results: Sixty-seven percent of patients presented via breast screening and 55% of all cases were diagnosed preoperatively on fine needle aspiration c ytology ([FNAC] ie, C5). Overall, 45% of patients had clear margins after i nitial local excision. Positive margins showed a nonsignificant trend of as sociation with distribution of microcalcifications (MCC), nonconsultant ope rating surgeon, inconclusive preoperative FNAC, presence of necrosis, and l ow specimen weight. There was a highly significant association between low grade DCIS (P = 0.003) and incomplete excision. There was no significant as sociation with age, associated invasive focus, morphology of MCC, or with m ode of presentation. Conclusion: Positive margins after local excision of DCIS are significantly associated with low nuclear grade, and preoperative determination of nucle ar grade by core biopsy may have surgical implications. (C) 2001 Excerpta M edica, Inc. All rights reserved.