Relationship between excision volume, margin status, and tumor size with the development of local recurrence patients with ductal carcinoma-in-situ treated with breast-conserving therapy

Background and Objectives: We reviewed our institution's experience treatin g patients with ductal carcinoma-in-situ (DCIS) with breast-conserving ther apy (BCT) to help define the interrelationship between excision volume, mar gin status, and tumor size with local recurrence. Methods: From January 1980 to December 1933, 146 patients received BCT for DCIS. All patients underwent excisional biopsy and 95 cases (64%) underwent re-excision. Each patient received whole breast radiation to a median dose of 45 Gy. An additional 139 cases (94%) received a supplemental boost to t he tumor bed (median total dose 60.4 Gy). The median follow-up is 7.2 years . Results: Seventeen patients developed an ipsilateral breast failure for a 5 -and 10-year actuarial rate of 10.2 and 12.4%, respectively. On multivariat e analysis, patient age, margin status, the number of slides containing DCI S, the number of DCIS/cancerization of lobules (COL) foci near (< 5mm) the margin, and a smaller volume of excision (< 60cm(3)) were all independently associated with outcome. Although the local recurrence rate generally decr eased as margin distance increased, these differences did not achieve stati stical significance unless the volume of excision was taken into considerat ion. Conclusions: These findings suggest that the success of BCT is directly rel ated to the deg:ree of surgical removal of DCIS and that margin status alon e may be suboptimal in defining excision adequacy. (C) 2001 Wiley-Liss, Inc .