HR and cancer: From 414 consecutive patients with HR+/HER2− MBC who had been treated with palbociclib plus ET from September 2018 to May 2022 in Peking University Cancer Hospital, we identified 80 patients who received abemaciclib plus switching ET or chemotherapy after progression on palbociclib, matched for age, original stage at diagnosis, disease‐free interval, and tumor burden at 1:1 ratio.