Risk factor of pneumonitis resulting from thoracic chemoradiotherapy combined with immunotherapy in lung cancer: A meta-analysis and systematic review

This study was a systematic review and meta-analysis of the risk factors associated with pneumonitis resulting from the combination of thoracic chemoradiotherapy (CRT) and immunotherapy in patients with lung cancer. A comprehensive search was conducted on PubMed, Web of Science, ScienceDirect, and Cochrane Library databases to identify clinical studies that investigated the risk factors for pneumonitis in patients with lung cancer undergoing CRT combined with immunotherapy. The study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and checklists. We analyzed 17 studies. Our comprehensive analysis identified volume (V) 20 and V40 as significant risk factors for pneumonitis in patients with lung cancer receiving CRT combined with immunotherapy (hazard ratio (HR) = 1.03, 95% confidence interval (95% CI) = 1.00-1.06). Additionally, body mass index ≥30 was a risk factor in a subset analysis (HR = 2.24, 95% CI = 1.12-4.48). In subset analyses, individuals aged ≥65 years had a higher risk of pneumonitis compared with those aged <65 years (HR = 1.39, 95% CI = 1.08-1.80), but this association was not significant when all age data were pooled (HR = 1.02, 95% CI = 0.99-1.05). Smoking was inversely associated with the risk of pneumonitis (HR = 0.93, 95% CI = 0.88-0.97). Race did not significantly affect the risk of pneumonitis, but whites had a lower risk compared with other races in subset es (HR = 0.78, 95% CI = 0.62-0.97). This meta-analysis and systematic review revealed that V20, V40, and body mass index ≥30 were significant risk factors for pneumonitis in patients with lung cancer receiving CRT combined with immunotherapy. Older patients also had a higher risk. Smoking history, however, was inversely associated with the risk of pneumonitis.