The unsatisfactory margin in breast cancer surgery

BACKGROUND: Surgical margin involvement with breast cancer usually results in obligatory reexcision or mastectomy, While unalterable occult host and p athologic factors may interfere with margin clearance during the initial ex cision, it is possible that alterations in surgical technique might increas e the likelihood of obtaining satisfactory margins. METHODS: TWO hundred and thirty-five patients who were candidates for breas t conservation therapy were identified for 1991 and 1996 using the Tumor Re gistry. Margins were defined as "unsatisfactory" if there was microscopic i nvolvement with tumor or the margin was close at initial excisional biopsy and the surgeon opted for reexcision. Multiple logistic regression analyses of factors associated with margin status were performed. RESULTS: One hundred thirty-two (56%) patients had positive or close (unsat isfactory) margins; this rate increased from 51% in 1991 to 59% in 1996, Pa tients with unsatisfactory margins underwent more procedures (mean 2.0 vers us 1.2; P < 0.0001) than patients whose margins were satisfactory. The brea st conservation rate for patients with unsatisfactory margins was 64% compa red with 99% for patients with satisfactory margins. A multiple logistic re gression demonstrated that patients with unsatisfactory margins were 67 tim es more likely to have a mastectomy than patients whose margins were satisf actory after adjusting for other significant factors (P < 0.0001). The prac tice of fine needle aspiration biopsy, orientation of specimen margins by t he surgeon, and reexcision of tumor at the first operation were statistical ly significant technical factors in obtaining satisfactory margins. Signifi cant pathology factors were extensive intraductal component (EIC), lobular or ductal extension, and tumor size, CONCLUSION: These data show that technical factors in the surgical manageme nt of breast cancer, as well as biological factors such as EIC, can influen ce the success of breast conservation. (C) 1999 by Excerpta Medica, Inc.