Lung Cancer Risk Attributable to Active Smoking in China: A Systematic Review and Meta-Analysis.

Objective: No consensus exists on the relative risk ( RR ) of lung cancer (LC) attributable to active smoking in China. This study aimed to evaluate the unified RR of LC attributable to active smoking among the Chinese population.
Methods: A systematic literature search of seven databases was conducted to identify studies reporting active smoking among smokers versus nonsmokers in China. Primary articles on LC providing risk estimates with their 95% confidence intervals ( CI s) for "ever" "former" or "current" smokers from China were selected. Meta-analysis was used to estimate the pooled RR of active smoking.
Results: Forty-four unique studies were included. Compared with that of nonsmokers, the pooled RR (95% CI ) for "ever" "former" and "current" smokers were 3.26 (2.79-3.82), 2.95 (1.71-5.08), and 5.16 (2.58-10.34) among men, 3.18 (2.78-3.63), 2.70 (2.08-3.51), and 4.27 (3.61-5.06) among women, and 2.71 (2.12-3.46), 2.66 (2.45-2.88), and 4.21 (3.25-5.45) in both sexes combined, respectively.
Conclusion: The RR of LC has remained relatively stable (range, 2-6) over the past four decades in China. Early quitting of smoking could reduce the RR to some extent; however, completely refraining from smoking is the best way to avoid its adverse effects.
(Copyright © 2023 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.)