Phase III multicenter trial of doxorubicin plus cyclophosphamide followed by paclitaxel compared with doxorubicin plus paclitaxel followed by weekly paclitaxel as adjuvant therapy for women with high-risk breast cancer.

Purpose: This study compared disease-free survival (DFS) obtained with two different regimens of adjuvant therapy in high-risk breast cancer.

Methods: Women (who had performance status [PS] of 0 to 1) with operable, histologically confirmed, stage I to III adenocarcinoma of the breast were eligible. Patients had undergone primary surgery with no residual tumor. Treatments were as follows: arm 1 was doxorubicin 60 mg/m(2) plus cyclophosphamide 600 mg/m(2) every 3 weeks for four cycles followed by paclitaxel 175 mg/m(2) every 3 weeks for four cycles (ie, AC-P); and arm 2 was doxorubicin 50 mg/m(2) plus paclitaxel 200 mg/m(2) every 3 weeks for four cycles followed by paclitaxel 80 mg/m(2) weekly for 12 weeks.

Results: Overall, 1,830 patients were enrolled and 1,801 were treated: arm 1 (n = 906; AC-->P) and arm 2 (n = 895; AP-WP). Overall, patients had a PS of 0 (88%), had estrogen receptor and progesterone receptor-positive disease (52%), had one to three positive nodes (46%), and were postmenopausal (57%); the median age was 52 years. Currently, 1,640 patients (90%) are alive. The 6-year DFS was 79% to 80% in both groups. Disease relapse was the cause of death for 83 patients in arm 1 and in 66 patients of arm 2. Overall 6-year survival rates were 82% and 87% in arms 1 and 2, respectively. Reasons for patients being taken off study treatment included toxicity (13% in arm 1 v 20% in arm 2), progressive disease or recurrence (7% v 5%), and consent withdrawn (9% v 8%), respectively. The most frequent toxicities were hematologic, including neutropenia and leukopenia followed by neuropathy, myalgia, nausea, fatigue, headache, arthralgia, and vomiting.

Conclusion: The results indicate that the AP-WP regimen is an equally effective and tolerable option for the adjuvant treatment of patients with high-risk breast cancer. The substitution of paclitaxel for cyclophosphamide results in comparable effectiveness of the regimen.