Predicting the likelihood of residual disease in women treated for ductal carcinoma in situ

Background: To identify women at risk for residual disease after excision o f ductal carcinoma in situ (DCIS), we assessed the relationship between cha racteristics of the initial biopsy and the presence of residual DCIS at a s ubsequent operation. Study Design: We identified 134 consecutive "paired" operations from 112 wo men who had undergone 2 or more operations for DCIS between February 1995 a nd December 1996. Cancer status of the margins, patient age and leading pre sentation, tumor subtype and grade, and the presence of multifocal-extensiv e disease were assessed as potential predictors. Results: Residual DCIS was found in 60 patients (45%): in 2 of 12 patients (17%) with negative margins, in 11 of 36 (31%) with close margins (< 2 mm), in 30 of 52 (58%) with positive margins, and in 17 of 34 patients (50%) wi th margins of unknown status. Patients with positive or unknown margins wer e 7.7 and 8.3 times, respectively, more likely to have residual disease tha n patients with negative margins (95% CI 1.1-59.1; 1.1-66.4). Patients with clinical presentations were 8.0 times more likely to have residual disease than patients who presented with abnormal mammograms (95% CI 2.3-27.6). Mu ltifocal-extensive DCIS was associated with residual disease (adjusted odds ratio [OR] = 7.7, 95% CI 2.9-20.5), as was comedo subtype (OR = 2.7, 95% C I 1.1-6.7). Conclusions: Positive or unknown biopsy margins, a clinical presentation, m ultifocal-extensive cancer, and the comedo subtype are associated with high er risk of residual DCIS. (J Am Coll Surg 1999;188:17-21. (C) 1999 by the A merican College of Surgeons).