FACTORS ASSOCIATED WITH A POSITIVE REEXCISION AFTER EXCISIONAL BIOPSYFOR INVASIVE BREAST-CANCER

Background. Breast-conserving therapy followed by adjuvant radiotherap y represents an alternative to mastectomy as a treatment for invasive breast cancer. When excisional biopsy has been performed outside the p arent institution, reexcision is often performed, with tumor being ide ntified in 32% to 62% of the subsequent specimens. We analyzed not onl y the factors associated with a positive reexcision but also those fac tors associated with final surgical margins that are positive for tumo r. Methods. Between 1978 and 1998, 956 female patients with American J oint Committee on Cancer clinical stage I or II breast cancer were tre ated with breast-conserving therapy where a total of 420 patients unde rwent reexcision after an initial excisional biopsy. Several factors w ere analyzed to determine their association with a positive reexcision , the status of the final surgical margin, and the nature of the disea se present within the reexcision specimen. Results. Factors that corre lated with a positive reexcision in both univariate and multivariate a nalysis were clinical tumor size, method of detection, the pathologic status of the axillary lymph nodes, and the histologic appearance. Tho se factors associated with finding invasive disease at the time of ree xcision were clinical tumor size, clinical presentation, and nodal sta tus. The single factor associated with finding residual in situ diseas e at the time of reexcision was histologic appearance of the primary t umor. A final positive margin was associated with method of tumor dete ction, age of the patient, and the presence of axillary lymph node met astases. The most significant factors associated with a positive reexc ision are clinical tumor size, method of tumor detection, pathologic n odal status, and histologic appearance. Patients with larger tumors or those that are detected by physical examination, as well as invasive lobular carcinomas, may require a more generous initial resection to a chieve negative surgical margins and avoid the likelihood of reexcisio n.