[A Case of Drug-Induced Lung Injury That Developed the Day after Abemaciclib Treatment for Advanced Breast Cancer].

A 74-year-old woman was diagnosed with invasive breast ductal carcinoma, cT2N0M1 (PUL), stage Ⅳ, and treated with abemaciclib and letrozole. The day after drug administration, the patient developed a fever of 38℃ and dyspnea upon exertion, and was diagnosed with drug-induced pneumonia. Steroid pulse therapy was administered during hospitalization, and the patient was discharged after the dose of prednisolone was gradually reduced.