PURPOSE: Nodal involvement has long been known to represent the single most reliable indicator of the prognosis in early-stage breast cancer. In common parlance, high-risk node-positive breast cancer has generally been used to describe patients who have involvement of ten or more axillary lymph nodes (10 LN). Patients with 10 LN clearly have a strikingly high risk of recurrence and death. Thus we tried to evaluate the clinical courses of breast cancer patients with more than 10 positive axillary lymph nodes. METHODS: Of 587 breast cancer patients operated on at Chungnam National University Hospital from Feb. 1992 to Nob. 1999, 31 cases (5.3%) showed involvement of more than 10 axillary lymph nodes. We evaluated the clinical courses of these patients and differences in survival related to clinical and pathologic vaiables. Survival was calculated using the Kaplan-Meier method. RESULTS: The mean age of the patients was 50 14 years. A mastectomy was performed in 28 cases (90.3%), and a breast conserving operation in 3 cases (9.7%). The mean tumor size was 4.8 2.5 cm. The mean number of removed axillary LN was 23.5 10.2 (10-52), and the mean number of positive axillary LN was 20.0 10.1 (10-51). At a median follow-up of 30.5 months, 23 cases (74.2%) of recurrence were noted. Among these 69.6% (16/23) showed distant metastases as a first recurrence. The 3-year and 5-year disease-free survivals were 28.6% and 22.9%, respectively. The 3-year and 5-year expected overall survivals were 53.7% and 41.8%, respectively. There were significantly more recurrences in patients who had given up adjuvant chemotherapy than patients who had completed 6 cycles of FEC or MMM. Also, significant survival benefits were noted in patients who were treated using combination chemotherapy with taxane plus cisplatin after recurrence. CONCLUSION: Breast cancer patients with 10 LN have a strikingly high risk of recurrence. Six (6) cycles of adjuvant chemotherapy with FEC or MMM was a controllable variable for lowering the risk of recurrence. Also, combination chemotherapy with taxane and cisplatin was a controllable variable for increasing survival after recurrence.