Influence of breast cancer margin assessment method on the rates of positive margins and residual carcinoma

Background We hypothesized that the method of breast cancer margin assessment may be associated with different rates of positive margins and residual carcinoma. Methods A total of 178 breast cancer specimens were divided into 2 groups (A and B) based on the margin assessment method used. Rates of positive margins, re-excision, and residual carcinoma at re-excision were compared and analyzed statistically. Results At least 1 margin was positive in 64.7% in group A and in 65.2% in group B. At directed re-excision 54% in group A and 51% in group B had residual carcinoma. The lateral margin was positive in 44% in group A compared with 26% in group B (P = .06). The posterior margin was positive in 19% in group A and in 51% in group B (P = .001). Conclusions Two different breast cancer specimen margin assessment methods had comparable rates of positive margins and residual carcinoma at re-excision. Different patterns of specific margin positivity suggest that the method of margin assessment may alter results.