Pyrotinib for Elderly Patients with Advanced HER2-Positive Breast Cancer

INTRODUCTION: According to the latest global cancer data released by WHO in 2020, the incidence of breast cancer (BC) has been the most prevalent, and the mortality rate of female malignant tumor ranks the first. METHODS: To evaluate toxicity and efficacy regarding oral Pyrotinib for elderly patients with advanced HER2-positive breast cancer (BC) in Xinjiang, 45 elderly patients having advanced HER2-positive BC with age ≥65 years and receiving Pyrotinib-based combined therapy from January 2019 to May 2021 in Xinjiang were enrolled in this study. PFS, CBR, ORR and drug-related adverse events (AE) of oral Pyrotinib in the patients were retrospectively analyzed. All 45 patients completed the efficacy evaluation. RESULTS: Total ORR and CBR of the whole group was 37.8% and 77.8%, respectively. There were 14 patients with brain metastases (31.1%), with a median PFS of 6.8 months (95% CI: 5.4~9.8). In terms of the number of treatment lines, mPFS for line 1–2 was 8.3 months (95% CI: 6.3~11.4), and mPFS for line ≥3 was 3.3 months (95% CI: 2.7~5.1). At the final maintenance dose, mPFS at standard doses of 400mg, 320mg and 240mg were 9.1 months (95% CI: 4.1~9.5), 8.3 months (95% CI: 4.3~12.2) and 4.8 months (95% CI: 2.1~7.5), respectively. DISCUSSION: Applying Pyrotinib in elderly patients, the main adverse reaction was diarrhea, accounting for 88.9% (40/45). Pyrotinib is safe and effective for elderly patients with advanced HER2 positive BC.