Importance of radiation therapy for breast cancer patients treated with high-dose chemotherapy and stem cell transplant

Purpose: To determine local-regional failure rates in breast cancer patient s treated with surgery and high-dose chemotherapy with stem cell transplant and to relate local-regional failure to the use and timing of radiation tr eatment. Methods and Materials: We retrospectively reviewed the records of 165 breas t cancer patients treated on institutional protocols with surgery and high- dose chemotherapy with stem cell transplant. All patients had either Stage III disease, 10 or more positive axillary lymph nodes, or 4 or more positiv e axillary lymph nodes following neoadjuvant chemotherapy, Twelve patients had inflammatory breast cancer. Thirteen patients treated with breast prese rvation and 5 patients who died from toxicity within 30 days of transplant were excluded from the analyses of local-regional recurrences. In the remai ning 147 patients, 108 were treated with adjuvant radiation and 39 were not . The disease stage distribution for these two groups was comparable. The m edian follow-up for surviving patients was 35 months. Results: The 3- and 5-year actuarial disease-free survival (DFS) for the en tire group was 60% and 51%, respectively. The 5-gear rates of freedom from isolated local-regional recurrence were 95% in the patients treated with ad juvant radiation and 86% in the patients who did not receive radiation (p = 0,014, log rank comparison). The 5-year rates of any local-regional recurr ence as a first event (isolated recurrences plus those with simultaneous lo cal-regional and distant recurrences) were 92% versus 82%, respectively for patients whose treatment did and did not include radiation (p = 0,038), We could not demonstrate a correlation of the timing of radiation with the ri sk of Local-regional recurrence. Conclusions: These data indicate that high-dose chemotherapy does not negat e the importance of radiation in optimizing local-regional control in patie nts with high-risk breast cancer. Given the results of recent randomized tr ials studying postmastectomy radiation, which show that improving local-reg ional control improves overall survival (OS), we believe that all breast ca ncer patients with high-risk primary breast cancer who are treated with hig h-dose chemotherapy with stem cell transplant should receive radiation as a component of their treatment. (C) 2000 Elsevier Science Inc.