Bleomycin-Associated Pulmonary Toxicity in Adult Cancer Patients: Clinical Characteristics and Outcomes from a Single-Center Retrospective Cohort

Abstract

Background: Bleomycin remains an important component of curative-intent chemotherapy regimens for several malignancies, particularly Hodgkin lymphoma and germ cell tumors. However, bleomycin-associated pulmonary toxicity is a clinically important adverse effect that may lead to treatment interruption, hospitalization, respiratory failure, or irreversible pulmonary fibrosis. Real-world data from Middle Eastern oncology populations remain limited. Objectives: This study aimed to determine the frequency, clinical characteristics, and outcomes of bleomycin-associated pulmonary toxicity among adult patients with cancer treated at a tertiary care center. Methods: This single-center retrospective cohort study was conducted at King Abdullah Medical City, Makkah, Saudi Arabia. Adult patients with cancer who received at least one dose of bleomycin between January 2019 and June 2026 were identified through electronic health records and screened for eligibility. Data on demographic characteristics, cancer diagnosis, bleomycin indication and cumulative dose, pulmonary assessments, imaging findings, pulmonary function testing, toxicity grading, and clinical outcomes were extracted. The primary outcome was the proportion of patients with documented bleomycin-associated pulmonary toxicity during the available follow-up period. Secondary outcomes included pulmonary fibrosis, toxicity severity, oxygen requirement, mechanical ventilation, hospitalization, treatment modification or discontinuation, and recovery. Results: Among 117 patients, documented bleomycin-associated pulmonary toxicity occurred in 27 patients (23.1%; 95% confidence interval [CI], 15.8% - 31.8%), and pulmonary fibrosis occurred in 4 patients (3.4%; 95% CI, 0.9% - 8.5%). Post-bleomycin pulmonary function testing was documented in only 3 patients. Pulmonary toxicity was frequently accompanied by hospitalization, an oxygen requirement, and treatment modification. Recorded oxygen exposure was associated with pulmonary toxicity in an exploratory unadjusted analysis; however, its timing relative to toxicity onset was uncertain. The small number of events and incomplete documentation precluded reliable adjusted risk factor assessment. Conclusions: Bleomycin-associated pulmonary toxicity was documented in nearly one-quarter of adult patients with cancer receiving bleomycin, whereas pulmonary fibrosis was uncommon. These findings highlight the clinical impact of bleomycin-associated pulmonary toxicity and the need for standardized baseline and follow-up pulmonary assessments, particularly because post-treatment pulmonary function testing was rarely documented.