Pneumocystis jirovecii pneumonia (PCP)-related risk factors among patients with solid tumors are not completely defined. Thus, we aimed to characterize PCP cases with underlying solid tumors, to highlight the factors contributing to its development besides the prolonged use of moderate-to-high dose corticosteroids. We retrospectively reviewed the medical records of patients with solid tumors diagnosed with PCP between 2006 and 2018 at a cancer center in Tokyo, Japan. Demographic and clinical data were collected, which included malignancy types, total lymphocyte count, coexisting pulmonary disease, chemotherapy, radiation therapy, corticosteroid use, and PCP-attributable mortality. Twenty cases of PCP with solid tumors were documented in 151,718 patients and 788,914 patient-years. Lung cancer (n = 6, 30%) was the most common underlying tumor, followed by breast cancer (n = 3, 15%). Only six (30%) patients were taking a dosage of ≥20 mg prednisone equivalents daily for ≥4 weeks from the onset of PCP. Among the remaining 14 patients, seven (50%) had coexisting pulmonary diseases, 10 (71%) had received chemotherapy within 90 days prior to PCP diagnosis, seven (50%) had undergone chest radiation therapy before PCP diagnosis, seven (50%) had received only intermittent corticosteroids, and one (7%) received no corticosteroids. Mortality attributable to PCP was 40%. More than half of the patients were not taking a dosage of ≥20 mg prednisone equivalents daily for ≥4 weeks. Multiple other factors (e.g., lymphocytopenia, radiation to chest) may have potentially contributed to PCP in patients with solid tumors in a composite manner. We need to establish a method for estimating the likelihood of PCP taking multiple factors into account in this patient population.

中文翻译：

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实体瘤患者吉氏肺囊虫感染的临床特征及危险因素：大型癌症中心13年病历研究

实体瘤患者中耶氏肺孢子菌肺炎 (PCP) 相关的危险因素尚未完全确定。因此，我们旨在表征具有潜在实体瘤的 PCP 病例，以强调除了长期使用中至高剂量皮质类固醇外，促进其发展的因素。我们回顾性审查了 2006 年至 2018 年在日本东京癌症中心诊断为 PCP 的实体瘤患者的医疗记录。收集了人口统计学和临床​​数据，其中包括恶性肿瘤类型、总淋巴细胞计数、共存肺部疾病、化疗、放疗、皮质类固醇使用和 PCP 归因死亡率。在 151,718 名患者和 788,914 患者年中记录了 20 例患有实体瘤的 PCP。肺癌（n = 6, 30%）是最常见的潜在肿瘤，其次是乳腺癌（n = 3, 15%）。只有 6 名 (30%) 患者在 PCP 发病后 4 周内每天服用 ≥ 20 mg 泼尼松等效剂量。其余 14 名患者中，7 名 (50%) 合并肺部疾病，10 名 (71%) 在 PCP 诊断前 90 天内接受过化疗，7 名 (50%) 在 PCP 诊断前接受过胸部放疗，7 名 (50%) ) 仅接受过间歇性皮质类固醇治疗，其中一人 (7%) 未接受皮质类固醇治疗。归因于 PCP 的死亡率为 40%。超过一半的患者在 ≥4 周内没有每天服用≥20 mg 泼尼松当量的剂量。多种其他因素（例如，淋巴细胞减少、胸部放疗）可能以复合方式导致实体瘤患者的 PCP。