Pathologic and mammographic findings predicting the adequacy of tumor excision before breast-conserving therapy

OBJECTIVE. We performed a retrospective review to determine the need for reexcision after excisional biopsy in patients with breast cancer who are treated with breast-conserving therapy. MATERIALS AND METHODS. Eighty-seven patients with infiltrating ductal carcinoma of the breast underwent excisional biopsy followed by reexcision of the tumor site. Reexcision specimens were evaluated for residual disease and correlated with initial mammographic and pathologic findings. RESULTS. Tumors with an extensive intraductal componenet (EIC) were more likely to have residual disease at reexcision than those without an EIC (65% versus 6%, p < .01). Initially positive margins did not predict residual disease at reexcision significantly better than did initially negative margins (29% versus 13%,p = .08). Suspicious mammographic calcifications, absence of a discernible mass detected mammographically, or both were associated with a significantly increased risk of residual disease at reexcision. By combining all features (EIC, margin status, and mammography), we found that subsets of patients had significantly different risks of residual disease, which ranged from 6% to 83% (p < .01). CONCLUSION. Mammographic and pathologic findings are useful in predicting the adequacy of breast resection before radiation therapy in patients treated with breast-conserving therapy. An EIC is the most useful predictor of residual disease at reexcision. When combined, EIC, margin status, and mammographic findings form a powerful tool to judge the need for reexcision before radiation therapy.