To evaluate the efficacy and safety of trastuzumab and pertuzumab combined with chemotherapy in neoadjuvant therapy for human epidermal growth factor receptor 2 (HER2) positive breast cancer.

A retrospective study was performed on cases of HER2-positive breast cancer treated with neoadjuvant therapy at Peking University Shenzhen Hospital from January 2019 to December 2021. The patients were divided into two groups to receive either the TCbHP regimen or the EC-THP regimen for neoadjuvant chemotherapy, respectively. All patients underwent neoadjuvant and surgical treatment. The clinicopathological parameters were compared between patients with pathological complete response (pCR) and those with non-complete response (non-PCR) after neoadjuvant chemotherapy.

The mean age of the patients was (45.22±9.17) years. Twenty-five patients received the TCbHP regimen and 24 received the EC-THP regimen. The overall pCR rate was 65.3% (32/49). The pCR rate was 76.0% (19/25) among patients receiving the TCbHP regimen and 54.2% (13/24) among those receiving the EC-THP regimen (P＞0.05). The proportion of patients with positive ER and PR status in the PCR group was lower than that of the non-PCR group after neoadjuvant chemotherapy (P＜0.05 for both), though there was no significant difference in age, tumor stage, Ki67 index, molecular type, or chemotherapy regimens between the two groups (P＞0.05 for all). There were significant differences in ER status and molecular type between the TCbHP regimen group and EC-THP regimen group (P＜0.05 for both). Compared with the EC-THP group, the incidence of thrombocytopenia and renal injury was higher in the TCbHP group (P＜0.05 for both), but there was no significant difference in the incidence of other adverse events between the two groups (P＞0.05 for all).

Both the TCbHP and EC-THP regimens may be useful neoadjuvant treatments for HER2-positive breast cancer. The pCR rate to the TCbHP regimen was higher than that to the EC-THP regimen. The incidence of thrombocytopenia and renal injury is higher in the TCbHP regimen. Both regimens have very good cardiac safety.