The number of tumor-free axillary lymph nodes removed as a prognostic parameter for node-negative breast cancer

Recently, there has been controversy about the relationship between the number of lymph nodes removed and survival of patients diagnosed with lymph node-negative breast cancer. To assess this relationship, 603 cases of lymph node-negative breast cancer with a median of 126 months of follow-up data were studied. Patients were stratified into two groups (Group A, 10 or fewer tumor-free lymph nodes removed; Group B, more than 10 tumor-free lymph nodes removed). The number of tumor-free lymph nodes in ipsilateral axillary resections as well as 5 other disease parameters were analyzed for prognostic value. Our results revealed that the risk of death from breast cancer was significantly associated with patient age, marital status, histologic grade, tumor size, and adjuvant therapy. The 5- and 10-year survival rates for patients with 10 or fewer tumor-free lymph nodes removed was 88.0% and 66.4%, respectively, compared with 69.2% and 51.1%, respectively, for patients with more than 10 tumor-free lymph nodes removed. For patients with 10 or fewer tumor-free lymph nodes removed, the adjusted hazard ratio (HR) for risk of death from breast cancer was 0.579 (95% confidence interval, 0.492-0.687, P < 0.001), independent of patient age, marital status, histologic grade, tumor size, and adjuvant therapy. Our study suggests that the number of tumor-free lymph nodes removed is an independent predictor in cases of lymph node-negative breast cancer.