Neoadjuvant docetaxel in locally advanced breast cancer

Neoadjuvant chemotherapy produces substantial increases in clinical response rates and rates of breast conserving therapy. Pathologic response rate, though generally low, is an important outcome as it is presumably associated with eradication of micrometastatic disease and may likely result in improved outcomes. Anthracyclines have long been considered the most efficacious chemotherapy agents for neoadjuvant therapy of early breast cancer. Unfortunately, not all patients respond to neoadjuvant anthracycline-based chemotherapy. In an effort to improve primary tumor response, docetaxel, an active agent in breast cancer, has been evaluated in the neoadjuvant setting. Several randomized trials, including the NSABP B-27, GEPAR-duo, and the Aberdeen trial, evaluating docetaxel in sequence with a doxorubicin-based neoadjuvant regimen have been reported, with encouraging findings. We designed the Aberdeen trial with two primary aims: (1) to evaluate primary docetaxel in patients that initially fail a neoadjuvant anthracycline-based polychemotherapy regimen, and (2) to compare a docetaxel-based neoadjuvant regimen with a standard anthracycline-based regimen in patients who do respond to the first four cycles of the anthracycline-based regimen. Eligible patients (n = 162) had previously untreated large (> or = 3 cm) or locally advanced (T3, T4, T x N2) breast cancer. All received four cycles of CVAP, after which clinical response was assessed. Responding patients were then randomized to four additional cycles of CVAP or to docetaxel 100 mg/m2 every 3 weeks for four cycles. Patients failing to respond to CVAP received the docetaxel regimen. After the first four cycles of CVAP, the overall response rate (ORR) was 67%. Ultimately, responses were higher in the group randomized to docetaxel compared with those continuing CVAP (cCR: 94% vs. 66%; p = 0.001; pCR 34% vs. 16%; p = 0.04). The addition of docetaxel improved overall survival and disease-free survival for patients responding to four cycles of CVAP as compared with those receiving eight cycles of CVAP. Relative dose intensity was higher and the incidence of severe leukopenia was lower in the group randomized to docetaxel. These data and data from the NSABP B-27 and GEPAR-duo trials strongly support a combined anthracycline/docetaxel regimen in the neoadjuvant setting.