Neoadjuvant therapy with doxorubicin-cyclophosphamide followed by weekly paclitaxel in early breast cancer: a retrospective analysis of 200 consecutive patients treated in a single center with a median follow-up of 9.5 years.

Purpose: We analyzed outcomes of doxorubicin-cyclophosphamide (AC) followed by weekly paclitaxel as neoadjuvant chemotherapy (NAC) for breast cancer (BC), in an everyday practice with long-term follow-up of patients.

Methods: All patients (n = 200) who received the AC-paclitaxel combination as NAC for BC at the Soroka University Medical Center from 2003 to 2012 were included in this retrospective cohort study. AC was administered on an every 3-week schedule (standard dose) until May, 2007 (n = 99); and subsequently every 2-week dose dense (dd) (n = 101). Clinical pathologic features, treatment course, and outcome information were recorded. Complete pathologic response (pCR) was analyzed according to BC subtype, dose regimen, and stage.

Results: Median age was 49 years; 55.5% and 44.5% of patients were clinically stage 2 and 3, respectively. Standard dose patients had more T3 tumors. Subtypes were human epidermal growth factor receptor-2 (HER2)-positive 32.5% (of whom 82% received trastuzumab), hormone receptor-positive/HER2-negative 53%, and triple negative 14.5%. Breast-conserving surgery (BCS) was performed in 48.5% of patients; only 9.5% were deemed suitable for BCS prior to NAC. Toxicity was acceptable. The overall pCR rate was 26.0% and was significantly higher in the dd group and HER2-positive patients. With a median follow-up of 9.51 years median event-free survival (EFS) and overall survival (OS) are 10.85 years and 12.61 years, respectively. Patients achieving pCR had significantly longer EFS and OS.

Conclusion: NAC for BC with AC-paclitaxel can be safely administered in the "real-world' setting with high efficacy. Current efforts are aimed at increasing rates of pCR and identifying patients who may benefit from additional therapy or conversely, de-escalated treatment.