Impact of high-dose chemotherapy on the ability to deliver subsequent local-regional radiotherapy for breast cancer: analysis of Cancer and Leukemia Group B Protocol 9082.

PURPOSE: To report, from Cancer and Leukemia Group B Protocol 9082, the impact of high-dose cyclophosphamide, cisplatin, and BCNU (HD-CPB) vs. intermediate-dose CPB (ID-CPB) on the ability to start and complete the planned course of local-regional radiotherapy (RT) for women with breast cancer involving >or=10 axillary nodes. METHODS AND MATERIALS: From 1991 to 1998, 785 patients were randomized. The HD-CPB and ID-CPB arms were balanced regarding patient characteristics. The HD-CPB and ID-CPB arms were compared on the probability of RT initiation, interruption, modification, or incompleteness. The impact of clinical variables and interactions between variables were also assessed. RESULTS: Radiotherapy was initiated in 82% (325 of 394) of HD-CPB vs. 92% (360 of 391) of ID-CPB patients (p = 0.001). On multivariate analyses, RT was less likely given to patients who were randomized to HD treatment (odds ratio [OR] = 0 .38, p < 0.001), older (p = 0.005), African American (p = 0.003), postmastectomy (p = 0.02), or estrogen receptor positive (p = 0.03). High-dose treatment had a higher rate of RT interruption (21% vs. 12%, p = 0.001, OR = 2.05), modification (29% vs. 14%, p = 0.001, OR = 2.46), and early termination of RT (9% vs. 2%, p = 0.0001, OR = 5.35), compared with ID. CONCLUSION: Treatment arm significantly related to initiation, interruption, modification, and early termination of RT. Patients randomized to HD-CPB were less likely to initiate RT, and of those who did, they were more likely to have RT interrupted, modified, and terminated earlier than those randomized to ID-CPB. The observed lower incidence of RT usage in African Americans vs. non-African Americans warrants further study.

Consolidation with high-dose combination alkylating agents with bone marrow transplantation significantly improves disease-free survival in hormone-insensitive metastatic breast cancer in complete remission compared with intensive standard-dose chemotherapy alone.

We conducted this study to determine event-free and overall survival among women with hormone-insensitive or hormone-resistant metastatic breast cancer receiving consolidation with high-dose chemotherapy (HDC) and hematopoietic support versus no further chemotherapy after intensive induction chemotherapy. Eligible patients received induction doxorubicin, 5-fluorouracil, and methotrexate (AFM) for 2 to 4 cycles. Women in complete remission were randomized to immediate HDC with cyclophosphamide, cisplatin, and carmustine followed by autologous hematopoietic support or to no further therapy. Patients on the observation arm of therapy were offered salvage HDC at the time of relapse. Partial responders to AFM were offered immediate HDC. A total of 425 patients were enrolled onto the study. The median event-free survival for women randomized to induction therapy alone was 3.8 months, compared with 9.7 months for women who completed HDC (P < .006). Of the patients randomized to observation, 5 (10%) of 51 remain event free, compared with 13 (26%) of 49 patients who underwent immediate HDC (P = .03). Of women converted to a complete response by salvage HDC after a partial response to AFM, overall survival was similar to that in women randomized to immediate HDC. Follow-up is now in excess of 5 years. The 5-year event-free survival is 15% (95% confidence interval, 12%-18%), and the 5-year overall survival is 20% (95% confidence interval, 17%-25%). Immediate HDC after a complete response to AFM produced some durable long-term responses in hormone-insensitive/-resistant metastatic breast cancer. Salvage HDC converted 30% of partial responders to complete responders with similar survivals. The addition of novel targeted therapies to intensive-dose chemotherapy regimens may further improve survival in metastatic breast cancer.