Predicting local recurrence following breast conserving therapy for early stage breast cancer : the significance of a narrow (less than or equal to 2mm) surgical resection margin

Abstract

Introduction Controversy continues over the extent of surgical resection margin required to minimize the risk of local recurrence (LR) in breast conserving therapy (BCT) for stage I and II breast cancer. This thesis explores whether or not a narrow (less than or equal to 2 mm) but negative resection margin in BCT for stage I and II breast cancer affects LR. Methodology To address the question, all patients registered at the Saskatoon Cancer Center between January 1, 1991 and December 31, 2000 with a diagnosis of stage I or II invasive duct carcinoma of the breast treated with BCT were examined. All charts and pathology reports were reviewed with a review of the pathology for all cases where the resection margin was unclear in the original report. Other factors know or thought to effect LR (age, radiation boost, grade, extensive duct carcinoma in situ, ER/PR receptor status, tumor size, and systemic adjuvant therapy) were considered in the statistical analysis. Results Amongst the 200 narrow margin cases 19 LR were detected (19/200=9.5%) while 52 LR were detected in the 491 wide margin cases (52/491=10.6%). This difference was not statistically significant. Conclusions A narrow (less than or equal to 2 mm) surgical resection margin does not result in an increase in local recurrence compared to a surgical resection margin greater than 2 mm in breast conserving therapy for early stage duct carcinoma and does not warrant re-excision