CAN LOCAL EXCISION BE ADEQUATE IN THE TREATMENT OF DUCTAL CARCINOMA IN SITU?

Abstract

In this study, the medical records of 46 patients with ductal carcinoma in situ (DCIS) who were treated with mastectomy between 1989 and 1999 after excisional biopsy were reviewed retrospectively. The clinico-pathologic features at diagnosis which could be related to residual tumour in mastectomy specimens were evaluated by the univariate and multivariate statistical tests. There were residual tumours in mastectomy specimens of 28 cases (60.9%). The rates of residual tumour were 100% (15/15) for patients with positive surgical margin, 53.8% (7/13) for those with close margin (>2mm), and 27.8% (5/18) for those with negative margin (>2mm). in multivariate logistic regression analysis, multifocal disease, comedo subtype and surgical margin status were the most important independent factors related to residual tumors in mastectomy specimen. In the patients with unifocal DCIS who had non-comedo subtype, the probability of residual tumour were 10% for negative margin, 20% for close margin, and 100% for positive margin. In those with multifocal disease and comedo subtype, this probability was 100% regardless of surgical margin status. We conclude that the probability of residual tumour related to the factors mentioned above must be taken into consideration where local excision for the treatment of ductal carcinoma in situ is planned