The efficacy and safety of using pyrotinib combined with capecitabine as neoadjuvant therapy in elderly patients with HER2-positive breast cancer: a single-arm prospective clinical trial

BACKGROUND: Pyrotinib combined with capecitabine has been approved for the treatment of patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer in China. To date, the management of early-stage or locally advanced HER2-positive breast cancer in the clinic remains challenging. We conducted this trial to investigate the efficacy and safety of pyrotinib combined with capecitabine as neoadjuvant therapy (NAT) in elderly patients with HER2-positive breast cancer. Due to the stimulation of blood vessels by chemotherapy drugs, the elasticity of blood vessels in the elderly decreases, and then chemotherapy infusion is more likely to lead to phlebitis. Both pyrotinib and capecitabine can be taken to facilitate home treatment for elderly patients with HER2-positive breast cancer (BC). METHODS: From January 2020 to March 2021, patients aged between 70 and 81 years old with stage IIA–IIIB HER2-positive breast cancer were screened, enrolled, and assigned to receive six cycles of pyrotinib (320–400 mg, orally, once daily) plus capecitabine (1,250 mg/m(2), orally, twice daily) on days 1–14 in every 21-day cycle. The primary endpoint was the objective response rate (ORR). Adverse events (AEs) were assessed in every neoadjuvant cycle. Surgery was performed after the last cycle, and the total pathological complete response (tpCR) was evaluated postoperatively. RESULTS: Of the 23 patients enrolled, the ORR was 100% (23/23; 95% confidence intervals: 85 to 100). All patients underwent surgery with a tpCR rate of 43.5% (10/23; 95% confidence intervals: 23 to 66). The most common AE was diarrhea, occurring in 19 of 23 patients (82.6%); most of these patients sustained mild diarrhea (Grade 1 or Grade 2) and only three had moderate diarrhea (Grade 3). The incidences of other AEs, including weakness, loss of appetite, leukopenia, nausea, vomiting, hand-foot syndrome, etc., were low and the symptoms were mild. No severe AEs (Grade 4 or 5) were observed throughout the treatment. CONCLUSION: In our study, pyrotinib combined with capecitabine as neoadjuvant therapy in elderly women with HER2-positive breast cancer is safe and showed efficacy in this population, which may be widely used as a protocol for clinical neoadjuvant therapy.