Two Cases of Pneumocystis Pneumonia during Adjuvant Chemotherapy for Breast Cancer

In recent years, human immunodeficiency virus(HIV)-negative Pneumocystis pneumonia(PCP)onset has been occasionally seen in breast cancer. In particular, dose-dense epirubicin and cyclophosphamide(EC: ddEC)therapy, in which EC is administered every 2 weeks, has been generally used in clinical practice for early stage breast cancers. PCP may develop before and during postoperative chemotherapy. We report the cases of 2 patients who developed PCP during postoperative adjuvant chemotherapy. Case 1: A 62-year-old woman, who underwent postoperative EC therapy, developed PCP during the 4th EC cycle. During EC therapy, steroids(prednisolone[PSL])were administered at an average dose of 11.4mg/day, and the number of lymphocytes at the initiation of the 4th EC cycle was 516/mL. Case 2: After receiving 4 cycles of postoperative ddEC, a 27-year-old woman developed PCP after 1 cycle of docetaxel(DTX)administration. During ddEC therapy, PSL was administered at a dose of 17.14mg/day, and the number of lymphocytes at DTX administration was 311/mL. The onset of PCP is presumed to be related to the steroid dose administered and the number of lymphocytes. Therefore, determining effective indicators in patients at a high risk of PCP onset is important.