Efficacy and safety of neoadjuvant concomitant polychemotherapy (TEC) versus dose-dense regimen in luminal breast cancer.

Abstract

e12662 Background: Dose-dense (DD) chemotherapy is considered standard in localized breast cancer, but has not been directly compared with the concomitant docetaxel–epirubicin–cyclophosphamide (TEC) regimen in the neoadjuvant setting for luminal tumors. The objective of our study is to compare efficacy and safety of TEC versus DD in real-world clinical practice in the Huelva area. Methods: Retrospective observational study including patients (Pts) with luminal breast cancer treated with neoadjuvant chemotherapy at a single institution in the Huelva area (Spain). Pts received either TEC (docetaxel, epirubicin, cyclophosphamide q21d with peg/filgrastim) or DD (epirubicin–cyclophosphamide followed by paclitaxel q14d with peg/filgrastim). Radiological response, pathological complete response (pCR), Residual Cancer Burden (RCB), and toxicity were analyzed. SPSS Statistics 22 was used for data analysis. Results: Sixty-four Pts were included (TEC n = 35; DD n = 29). Median age was 46 vs 48 years. The DD group had worse baseline features, with higher stage III disease (72% vs 38%) and node-positive status (96% vs 53%). A total of 188 TEC and 172 DD cycles were administered. Toxicity was comparable: TEC was associated with grade 1–2 asthenia (35%), hematological toxicity (40%), gastrointestinal toxicity (19%) and low neurotoxicity (4%). DD showed similar asthenia (36%), higher neurotoxicity (18%), and lower hematological toxicity (20%). Overall complication rate per cycle was 32% with TEC and 31% with DD. Radiological complete response was 14.7% with TEC vs 10.5% with DD; partial response was 50% vs 79%, respectively. pCR rates were low (8% TEC vs 3% DD). Among evaluable patients (n = 52), RCB 0–1 was significantly higher with TEC compared with DD (61.8% vs 11.1%; OR 12.9, 95% CI 2.5–65.6; p < 0.001). In multivariable analysis, TEC was independently associated with a higher probability of achieving RCB 0–1 (OR 12.5, 95% CI 1.8–85.4; p = 0.010), while stage III disease was associated with lower response (OR 0.31, 95% CI 0.12–0.78; p = 0.001). Conclusions: In luminal breast cancer, neoadjuvant chemotherapy achieved low pCR rates. Despite poorer baseline prognosis in the DD group, TEC was not inferior and was independently associated with a higher probability of favorable pathological response. TEC showed comparable safety, with higher hematological but lower neurotoxicity than DD.