Local-regional recurrence in breast cancer after mastectomy and adriamycin-based adjuvant chemotherapy: evaluation of the role of postoperative radiotherapy.

In an attempt to determine whether patients treated for breast cancer with radical or modified radical mastectomy and adjuvant chemotherapy benefit from postoperative radiotherapy, 400 women with Stages II-III breast cancer who received adjuvant chemotherapy based on the combination of Adriamycin and Cytoxan were analyzed retrospectively. Prognostic features which predicted a high risk of isolated local-regional relapse were identified. Thirty-eight percent of these patients were also treated with postoperative radiation in addition to adjuvant chemotherapy and were compared to those patients treated only with adjuvant chemotherapy. With a median follow-up of 60 months, 15% of the patients reviewed developed local-regional disease as the first site of relapse without concommitant systemic relapse. When examined univariately, stage of disease, tumor size, nodal status, and estrogen receptor status were strong prognostic variables. Age, cell type, location of tumor within the breast, menstrual status, radiation dose, and type of treatment were not significantly related to isolated local-regional relapse. However, patients who received postoperative radiation were significantly more advanced in their disease condition. When the factors were examined multivariately, the type of treatment along with stage of disease were found to be statistically significant prognostic indicators. About half of the patients were tested for estrogen receptor status. Multivariate analysis performed on this subset of patients showed that estrogen receptor status, type of treatment, and axillary nodal status were significant predictors of the risk of isolated local-regional relapse. This study suggests that patients treated with mastectomy and Adriamycin and Cytoxan-based adjuvant chemotherapy may benefit from postoperative radiation in reducing the risk of isolated local-regional recurrence.