Objective  To compare the efficacy of taxane + carboplatin combined with trastuzumab and pertuzumab (TCbHP), taxane combined with trastuzumab and pertuzumab (THP) and anthracycline + cyclophosphamide followed by taxane + trastuzumab + pertuzumab (AC-THP) as neoadjuvant therapy strategies for breast cancer patients with human epidermal growth factor receptor-2 (HER-2) positive hormone receptor (HR) positive and HER-2 positive HR negative cancers, respectively.

  Methods  We retrospectively analyzed clinicopathological data of 408 HER-2 positive breast cancer patients receiving standard neoadjuvant therapy from Tianjin Medical University Cancer Institute & Hospital from June 2019 to December 2022. Stratified by HR, 211 of 408 were HER-2 positive HR positive, and 197 of 408 were HER-2 positive HR negative. Participants were further assigned into a TCbHP group, a THP group, and an AC-THP group according to their differing neoadjuvant regimens, and their pathologic complete response (pCR) rates were compared.

  Results  Among the HER-2 positive HR positive patients, the respective pCR rates of the TCbHP, THP, and AC-THP groups were 43.1% (69/160), 36.0% (9/25), and 38.5% (10/26) with no statistical significance (χ²=0.580, P=0.748). Among the HER-2 positive HR negative patients, the respective pCR rates of the TCbHP, THP, and AC-THP groups were 85.5% (94/110), 57.3% (43/75), and 66.7% (8/12) with a statistically significant difference between the TCbHP and THP groups (χ²=19.967, P<0.001).

  Conclusions  TCbHP, THP, and AC-THP as neoadjuvant regimens exerted similar efficacy in treating HER-2 positive HR positive breast cancer. TCbHP exhibited superior efficacy in HER-2 positive HR negative breast cancer.