Impact of chemotherapy regimens prior to endocrine therapy: Results from the ATAC (Anastrozole and Tamoxifen, Alone or in Combination) trial.

Background: The 33-month median follow-up of the ATAC (anastrozole and tamoxifen, alone or in combination) trial showed a potential interaction between anastrozole and previous chemotherapy; however, this was much smaller at 47 months' median follow-up. When the effects of different chemotherapy regimens were evaluated at that time, the apparent interaction was limited to patients who had received cyclophosphamide, methotrexate, and 5-fluorouracil (CMF).

Methods: In this retrospective analysis of 68-month data, we investigated the impact of prior chemotherapy, including different chemotherapy regimens, on time to recurrence.