Pneumocystis Pneumonia in Locally Advanced Breast Cancer Despite Prophylactic Use of Trimethoprim-Sulfamethoxazole During Prednisolone Treatment for a Pembrolizumab-Induced Immune-Related Adverse Event: A Case Report

Yudai Kaneda; Kenji Gonda; Takanori Asakura; Masahiro Wada; Toyoaki Sawano; Tomohiro Kurokawa; Kazunoshin Tachibana; Akihiko Ozaki

doi:10.7759/cureus.56868

Pneumocystis Pneumonia in Locally Advanced Breast Cancer Despite Prophylactic Use of Trimethoprim-Sulfamethoxazole During Prednisolone Treatment for a Pembrolizumab-Induced Immune-Related Adverse Event: A Case Report

Cureus. 2024 Mar 25;16(3):e56868. doi: 10.7759/cureus.56868. eCollection 2024 Mar.

Authors

Yudai Kaneda¹, Kenji Gonda², Takanori Asakura³, Masahiro Wada², Toyoaki Sawano⁴, Tomohiro Kurokawa⁴, Kazunoshin Tachibana², Akihiko Ozaki²

Affiliations

¹ School of Medicine, Hokkaido University, Sapporo, JPN.
² Department of Breast Surgery, Jyoban Hospital, Iwaki, JPN.
³ Division of Pulmonology, Kitasato University Hospital, Tokyo, JPN.
⁴ Department of Surgery, Jyoban Hospital, Iwaki, JPN.

Abstract

Pneumocystis pneumonia (PCP) primarily affects immunosuppressed patients, with trimethoprim-sulfamethoxazole (TMP-SMX) commonly used for prophylaxis. However, there is insufficient information on PCP occurrence despite TMP-SMX prophylaxis. We encountered a 57-year-old woman with locally advanced breast cancer developing PCP despite prophylactic intake of TMP-SMX, during treatment with prednisolone for Stevens-Johnson syndrome (SJS) induced by pembrolizumab. This case underscores the need to pay attention to the possibility of PCP development even during TMP-SMX prophylaxis. Dosage and duration adjustments according to the patient's condition and weight may be required.

Keywords: breast cancer; pneumocystis pneumonia (pcp); prophylaxis; stevens-johnson syndrome (sjs); trimethoprim-sulfamethoxazole (tmp-smx).

Publication types

Case Reports