Patient selection for breast conservation therapy with magnification mammography

Breast-conserving therapy (BCT) is an appropriate treatment for women with breast carcinoma of limited extent. This study was undertaken to determine the ability of microfocal spot magnification mammography to identify women with multifocal or multicentric breast carcinoma who were unlikely to have all gross carcinoma removed with a limited breast resection.

Two hundred sixty-three women with mammographically visible ductal carcinoma in situ and stage 1 and 2 carcinoma who were clinical candidates for BCT were evaluated with magnification mammography before undergoing definitive local therapy. Biopsy specimens of additional abnormalities thought to have a greater than 2% risk of malignancy were obtained.

Forty-seven women had other abnormalities in the index breast requiring intervention, and 216 had only the primary tumor identified. Mean age, cancer presentation, disease stage, and histologic tumor type did not differ between groups. BCT was successful in 97.2% of women without mammographic abnormalities versus 38% of women with abnormalities (p = 0.001). Clinical characteristics did not differ between patients undergoing successful BCT and those requiring mastectomy. Synchronous contralateral carcinoma was identified in 2.4% of women at risk.

Magnification mammography allows accurate preoperative identification of patients requiring mastectomy or quadrantectomy and should be performed before diagnostic biopsy is done.