Adjuvant Chemotherapy in Older and Younger Women With Lymph Node–Positive Breast Cancer

CONTEXT Adjuvant chemotherapy improves survival for patients with local-regional breast cancer, but healthy older patients at high risk of recurrence are frequently not offered adjuvant chemotherapy, and the benefit of adjuvant chemotherapy in older patients is uncertain. OBJECTIVE To compare the benefits and toxic effects of adjuvant chemotherapy among breast cancer patients in age groups of 50 years or younger, 51 to 64 years, and 65 years or older. DESIGN AND SETTING Retrospective review of data from 4 randomized trials that accrued patients from academic and community medical centers between 1975 and 1999. Median follow-up for all patients was 9.6 years. All trials randomized patients to different regimens, doses, schedules, and durations of chemotherapy and all had a treatment arm with doses or schedules that were regarded to be “high” and potentially more toxic. PATIENTS A total of 6487 women with lymph node–positive breast cancer; 542 (8%) patients were 65 years or older and 159 (2%) were 70 years or older. MAIN OUTCOME MEASURE Comparison of disease-free survival, overall survival, and treatment-related mortality among different age groups. RESULTS Multivariate analysis showed that smaller tumor size, fewer positive lymph nodes, more chemotherapy, and tamoxifen use were all significantly (P