To investigate the adverse events of trastuzumab (H) + pertuzumab (P) combined with taxanes (T) + carboplatin (C) (TCHP) neoadjuvant therapy in patients with human epidermal growth factor receptor 2 (HER2) positive breast cancer.

The clinical data of patients with HER2 positive breast cancer who received neoadjuvant therapy with the TCHP regimen and underwent surgery at the Breast Disease Center of Peking University First Hospital from March 2019 to October 20120 were analyzed retrospectively. The TCHP regimen was repeated every 21 days and granulocyte colony stimulating factor (G-CSF) was used prophylactically. A retrospective analysis of the adverse events was conducted during the treatment period. Adverse events were evaluated with Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Full-time clinical pharmacists were responsible for following, recording, and evaluating the adverse reactions in each cycle.

A total of 56 patients were included in the analysis; all of them were female. The average age was 48 years (range, 24-68 years), and the average number of treatment cycles were 3.7. Among the patients included, only one had no adverse events related to the TCHP regimen, and the patient was followed for only one cycle. Overall, the incidence of treatment-related adverse events was 98.2% (55/56), and the incidence of grade adverse events of grade 3 or above was 35.7% (20/56). Adverse events with a high incidence are listed as follows: diarrhea (49/56, 87.5%), fatigue (47/56, 83.9%), nausea (44/56, 78.5%), anorexia (37/56, 66.0%), and constipation (34/56, 60.7%). Under the monitoring and follow-up by pharmacists and doctors, the patients were treated with G-CSF every cycle, and the incidence of leukopenia and neutropenia was low.

The incidence of adverse events in breast cancer patients who receive the TCHP regimen is high. The common adverse events associated with this regimen are diarrhea, fatigue, nausea, anorexia, and constipation. Treatment-related adverse events of grade 3 or above include anorexia, nausea, diarrhea, and neutropenia.