Prospective, randomized comparison of high-dose chemotherapy with stem-cell support versus intermediate-dose chemotherapy after surgery and adjuvant chemotherapy in women with high-risk primary breast cancer: a report of CALGB 9082, SWOG 9114, and NCIC MA-13

Abstract

Purpose: The prognosis for women with primary breast cancer involving multiple axillary nodes remains poor. High-dose chemotherapy with stem-cell support produced promising results in initial clinical trials conducted at single institutions.

Patients and methods: Seven hundred eighty-five women aged 22 to 66 years with stage IIA, IIB, or IIIA breast cancer involving 10 or more axillary lymph nodes were randomized after surgery and standard adjuvant chemotherapy to either high-dose cyclophosphamide, cisplatin, and carmustine (HD-CPB) with stem-cell support or intermediate-dose cyclophosphamide, cisplatin, and carmustine (ID-CPB) with G-CSF support but without stem cells. Planned treatment for all patients included locoregional radiation therapy. Hormone-receptor-positive patients were to receive 5 years of tamoxifen. Event-free survival (EFS) was the primary end point.

Results: Median follow-up was 7.3 years. Event-free survival was not significantly different between the two treatment groups (P = .24). The probability of being free of an event at 5 years with HD-CPB was 61% (95% CI, 56% to 65%), and was 58% (95% CI, 53% to 63%) for ID-CPB. Thirty-three patients died of causes attributed to HD-CPB, compared with no therapy-related deaths among women treated with ID-CPB. Overall survival for the two arms was identical at 71% at 5 years (P = .75).

Conclusion: HD-CPB with stem-cell support was not superior to ID-CPB for event-free or overall survival among all randomized women with high-risk primary breast cancer.