Incidence of Pneumonitis in Asian Patients With Lung Cancer: A Systematic Literature Review and Meta-analysis

Pneumonitis is a notable toxicity of lung cancer therapies, particularly radiation and immune checkpoint inhibitors. Racial and ethnic disparities in pneumonitis risk exist, yet heterogeneity remains understudied. This study aimed to quantify pneumonitis incidence among East and Southeast Asian patients treated for non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). A systematic literature review (SLR) and single-arm meta-analysis were conducted following Cochrane and PRISMA guidelines. MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and 5 local language databases were searched for studies published from January 1, 2014 to August 2, 2023. Included were clinical trials in Asian patients undergoing pharmacological or radiation therapy for NSCLC or SCLC. The SLR included 218 trials (NSCLC: 202, SCLC: 16). Pooled incidence of all-grade, grade 1 to 2, and grade 3 to 5 pneumonitis in NSCLC was 5.42% (95% CI, 4.25-6.89), 3.58% (95% CI, 2.54-5.03) and 1.34% (95% CI, 1.06-1.70), respectively. For SCLC, pooled incidence was 12.21% (95% CI, 4.77-27.85), 7.64% (95% CI, 2.48-21.23), and 2.43% (95% CI, 1.47-3.97), respectively. Significantly higher rates of pneumonitis were observed in patients receiving chemoradiation or radiation-containing treatments, in general, compared to those not treated with radiation; grade 3 to 5 events in SCLC were not significantly different. This study establishes baseline pneumonitis risk in East and Southeast Asian patients treated for NSCLC and SCLC, highlighting higher incidence in those receiving radiation-containing treatments, particularly for lower-grade events. The results help contextualize safety data from clinical trials enrolling Asian patients.