The risk of primary lung cancer in ANCA-associated vasculitis: systematic review and meta-analysis

Background Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a systemic inflammatory disorder that affects small blood vessels. However, the association between AAV and lung cancer risk remains uncertain. We performed a systematic review and meta-analysis to evaluate the relationship between AAV and the risk of lung cancer.Methods We systematically searched PubMed, Embase, Scopus, and Web of Science from inception through March 2025. Studies reporting relative risks (RRs), odds ratios (ORs), hazard ratios (HRs), or standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were included. SIRs were used to estimate relative risk versus the general population. Pooled RR and 95% CI were calculated using a random-effects model (DerSimonian and Laird). Heterogeneity and publication bias were assessed.Results Thirteen studies (11 cohort, 2 case-control) including 8004 participants were analyzed. The mean age at diagnosis was 58.83 ± 16.99 years, with 49.68% male. Follow-up ranged from 2 to 26 years. The pooled RR for lung cancer was 2.08 (95% CI, 1.52–2.83), indicating increased risk. Moderate heterogeneity was observed (I2 = 48.38%).Conclusion There is an increased risk of lung cancer in patients with AAV. Further studies are warranted to better elucidate the underlying mechanisms and guide appropriate screening strategies.