Adjuvant chemotherapy with six cycles of AC regimen versus three cycles of AC regimen followed by three cycles of Paclitaxel in node-positive breast cancer

Context: Antracycline-Cyclophosphamide (AC) along with Paclitaxel/Docetaxel, either in combination or sequential regimens, is showing superior results than Anthracycline-containing regimens. Aims: This study was designed to determine whether adding Paclitaxel to a standard adjuvant chemotherapy regimen AC for breast cancer patients would prolong the time to recurrence and survival. Settings and Design: Randomized, prospective, open-labeled, single-institutional study. Materials and Methods: Fifty stage II breast cancer patients accruing 25 patients in each arm, treated between July 2007 and January 2010, were included in the study. Initial surgical treatment was Modified Radical Mastectomy. Systemic therapy was to have begun within 4-6 weeks of the patients surgery. In the control arm, all the patients were treated with six cycles of adjuvant chemotherapy with AC regimen repeated at an interval of 3 weeks. For the study arm, the patients received adjuvant chemotherapy with three cycles of AC regimen followed by three cycles of Paclitaxel, repeated at an interval of 3 weeks. All the patients of both the arms received locoregional external beam radiotherapy (EBRT) after the entire course of chemotherapy. All the hormone receptor-positive patients received Tamoxifen. Statistical Analysis Used: Statistical analysis was performed using the chi-square test and the Kaplan Meier survival analysis with the log-rank (Mantel-Cox) test. Results: Adding Paclitaxel to AC resulted in a statistically significant disease-free survival. The overall survival was also improved significantly. The toxicity profile in both the arms was comparable. Conclusions: In early and node-positive breast cancer, the addition of three cycles of Paclitaxel after completion of three cycles of AC improves the disease-free and overall survival.