Prognostic significance of residual breast disease and axillary node involvement for patients who had primary induction chemotherapy for advanced breast cancer

Background: We performed this study to determine the prognostic significance of clinical tumor size, pathologic measurement of residual tumor, and number of positive axillary nodes in the surgical specimen relative to overall survival for patients who underwent primary induction chemotherapy for advanced breast cancer. Methods: Data, collected prospectively between 1997 and 2002, included clinical tumor-node-metastasis stage, age at diagnosis, hormone receptor status, type of preoperative chemotherapy, histological type, surgical procedure, pathologic measurement in centimeters of residual breast tumor, and the number of positive axillary nodes in the surgical specimen. Univariable correlates of residual breast disease were assessed by using the chi(2) test. Recursive partitioning analysis was used to determine the prognostic significance of clinical tumor size, residual tumor size, and pathologic node involvement relative to overall survival. Survival was estimated by using the method of Kaplan and Meier and compared by using the log-rank test. A P value of < .05 was considered significant. Results: Data were available for 85 patients with advanced breast cancer. Although univariable analysis identified increasing age, clinically involved axillary nodes, and a higher clinical tumor-node-metastasis stage as predictors of an increased risk of residual disease, recursive partitioning analysis identified more than three involved axillary nodes in the surgical specimen, with or without any measurable residual breast disease, as the most significant predictor of decreased survival (P < .001). Conclusions: Pathologic axillary node involvement was the most significant predictor of decreased survival for patients who had undergone primary induction chemotherapy for advanced breast cancer.