Antitumor activity and efficacy of shorter versus longer duration of anthracycline-taxane neoadjuvant chemotherapy in stage II-III HER2-negative breast cancer: a 10-year, retrospective analysis.

Background: Neoadjuvant anthracycline-taxane-based chemotherapy (ChT) is a standard of care treatment option for stage II-III breast cancer (BC) patients. However, the optimal duration of neoadjuvant ChT has been poorly investigated so far.

Material and methods: We retrospectively retrieved clinical data of patients with stage II-III human epidermal growth factor receptor 2-negative (HER2-) BC who were treated between October 2007 and January 2018 with neoadjuvant AT (doxorubicin-paclitaxel) for three cycles followed by CMF (cyclophosphamide-methotrexate-5-fluorouracil) for three cycles (cohort A) or with four AT cycles followed by four CMF cycles (cohort B). The aim of our study was to investigate the impact of neoadjuvant ChT duration (cohort A versus cohort B) on pathological complete response (pCR) rates, disease-free survival (DFS) and overall survival (OS).

Results: Of 209 HER2- BC patients included, 62 had triple-negative breast cancer (TNBC) and 147 had hormone receptor-positive (HR+) BC. Median age was 48 years (range 30-74 years). A total of 111 patients belonged to cohort A and 98 patients belonged to cohort B. pCR was detected in 29 (13.9%) patients, 25 (40.3%) of whom had TNBC and four (2.7%) had HR+ HER2- BC. Patients achieving pCR had significantly longer DFS and OS, with statistical significance reached only in patients with TNBC. We found no differences between cohort A and cohort B in terms of pCR rates (15.3% versus 12.2%; p  = 0.55), DFS ( p  = 0.49) or OS ( p  = 0.94). The incidence of grade 3/4 adverse events was similar in cohort A versus cohort B as well (22.5% versus 19.4%; p  = 0.54).

Conclusion: Shorter duration of neoadjuvant anthracycline-taxane ChT was not associated with worse clinical outcomes in patients with stage II-III BC. Prospective studies are needed to evaluate whether the duration of neoadjuvant anthracycline-taxane-based ChT can be reduced in specific patient subgroups without negatively affecting clinical outcomes.