Background: In 2000, cyclophosphamide(C), epirubicin(E) and fluorouracil (F) (CEF) and doxorubicin (A) and C followed by paclitaxel (T) (AC/T) given every three weeks were commonly used regimens in Canada and the USA to treat women with node positive or high risk node negative operable breast cancer. In a previous trial in women with locally advanced breast cancer, 3 months of dose-dense EC was equivalent to six months of CEF. We hypothesized that the addition of 3 months of a taxane following dose-dense EC would be superior to CEF alone or AC/T. In a randomized trial in women with early breast cancer we compared CEF, dose dense EC/T and AC/T. An interim analysis (JCO, 2010) conducted when 50% of the events for the relapse-free-survival (RFS) analysis were observed, demonstrated that AC/T administered every 3 weeks was significantly inferior to CEF or EC/T. The results of the final RFS including CEF versus EC/T will be presented.

Methods: Women, 60 years or younger, with operable axillary node positive or high risk node negative breast cancer were randomized to adjuvant CEF, EC/T or AC/T. CEF was given for 6 cycles and consisted of: C 75 mg/m2 orally on Days 1–14, and E 60 mg/m2 and F 500 mg/m2, IV on Days 1 and 8. CEF patients received concurrent antibiotic prophylaxis. EC/T consisted of 6 cycles of EC every 14 days; E 120 mg/m2 and C 830 mg/m2, both IV on Day 1 with filgrastim 5 [ug]/kg/day subcutaneous from Days 2–13 and epoetin alpha 40,000 units subcutaneous once weekly. After completion of EC, 4 cycles of T 175 mg/m2 every 21 days with filgrastim and epoetin alpha were given. The AC/T regimen consisted of A 60 mg/m2 and C 600 mg/m2 IV every 21 days for 4 cycles. This was followed by T 175 mg/m2 every 21 days for 4 cycles. The final analysis for RFS was planned when 453 events were observed permitting the detection of a hazard ratio (HR) of 1.43 between CEF and AC/T and a HR of 1.43 between EC/T and the best of the other two arms. Quality of Life data using the EORTC C-30 and the Breast Cancer Chemotherapy questionnaires were collected throughout the study. The results will be available at the time of the presentation.

Results: A total of 2104 women were enrolled between December 2000 and April 2005. The required 453 events for the RFS analysis were observed by the clinical cut-off date of March 30, 2012. At this point 369 deaths had been observed. The median follow-up is 87.5 months. Outstanding data and queries are currently being collected and reviewed with an expected database lock and final analysis mid August, 2012. Febrile neutropenia remains higher on the CEF and EC/T arms while more neuropathy was seen in the taxane containing regimens.

Conclusions: Although the two regimens considered a standard of care at the time the study was initiated are no longer widely used, the trial results will enhance our understanding of the magnitude of benefit of taxane following an anthracycline, the significance of cumulative anthracycline dose, and the role of dose density/ intensity as backbone of conventional chemo regimens.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-13-01.