ABSTRACT
Objective:To evaluate the efficacy of oral pyrotinib in treatment of patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer in the real world, and to explore its influencing factors.Methods:The clinical data of 148 patients with HER2-positive metastatic breast cancer treated with oral pyrrolitinib in Shanxi Cancer Hospital from September 2018 to December 2020 were retrospectively analyzed. The efficacy was evaluated according to the efficacy evaluation criteria for solid tumors, version 1.1, and the adverse effects were graded according to the National Cancer Institute common terminology criteria of adverse effects, version 4.0. The Kaplan-Meier method was used to draw progression-free survival (PFS) curves, the patients were stratified by different clinical characteristics, and log-rank test was used for univariate analysis of PFS; the multivariate analysis of PFS was performed using Cox proportional hazards model.Results:The objective response rate (ORR) of 148 patients was 71.6% (106/148), and the disease control rate (DCR) was 89.2% (132/148). The overall median PFS time was 11.0 months (95% CI 10.1-11.9 months), and the median PFS of 19 patients with brain metastases was 10.0 months (95% CI 7.4-12.6 months). The differences in PFS between patients stratified by disease-free interval (DFI), the number of metastatic site and Eastern Cooperative Oncology Group (ECOG) score were statistically significant (all P < 0.05), but the difference in PFS between patients with negative and positive hormone receptor was not statistically significant ( P > 0.05). Multivariate Cox regression analysis showed that DFI (>1 year vs. ≤1 year: HR = 5.254, 95% CI 0.728-37.933, P = 0.046) and ECOG score (≥2 points vs. 0-1 point: HR = 2.454, 95% CI 1.261-4.788, P = 0.008) were independent influencing factors of PFS. The most common ≥grade 3 adverse effects were diarrhea (31 cases, 20.9%) and hand-foot syndrome (38 cases, 25.8%). Conclusions:The pyrotinib has definite efficacy and good safety in the treatment of HER2-positive metastatic breast cancer in the real world, especially for patients with DFI > 1 year and ECOG score 0-1 point, the efficacy and safety are particularly good.