An exploration of the optimal combination chemotherapy regimen based on neoadjuvant therapy containing pyrotinib for HER2-positive breast cancer: A multicenter real-world study

Background: The combination of pyrotinib (Py) with cytotoxic agents proved to be effective in early human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC). However, the optimal chemotherapy regimen is unknown. This study attempts to explore it from real-world research data.

Methods: Information was collected from patients with early-stage HER2-positive BC from 23 centers across the country. They were categorized into the anthracycline group (A group) and non-anthracycline group (non-A group). Patients in the non-A group were further categorized into the platinum group and non-platinum group and the short-cycle (≤4 cycles) taxane group and long-cycle (>4 cycles) taxane group. Total pathological complete response (tpCR, ypT0/is ypN0) and breast pathological complete response (bpCR, ypT0/is) rates were assessed.

Results: A total of 107 patients were enrolled. Postoperative pathology indicated a tpCR rate of 36.8 %, a bpCR rate of 42.1 % in the A group, the non-A group had a tpCR rate of 47.8 %, and a bpCR rate of 53.6 %, with P-values of 0.273 and 0.254, respectively. In the long-cycle taxane group, the tpCR and bpCR rates were 60.8 % and 66.7 %, respectively. In the short-cycle taxane group, the tpCR and bpCR rates were 11.1 % and 16.7 %, respectively (both P<0.001). The platinum group had higher tpCR rate (62.9 % vs. 32.4 %, respectively; P = 0.011) and bpCR rate (65.7 % vs. 41.2 %, respectively; P = 0.041).

Conclusion: As for a neoadjuvant therapy regimen with Py, an anthracycline-free regimen is feasible. Besides, platinum-containing, long-cycle taxane regimens appear to achieve superior efficacy under anthracycline-removed conditions.