Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 23 4 2024 07 27 347 356 Zhihui Lin Department of Pulmonary and Critical Care Medicine, Ningbo Medical Center Lihuili Hospital, Ningbo, Zhejiang, China Li Yuan Department of Pulmonary and Critical Care Medicine, Ningbo Medical Center Lihuili Hospital, Ningbo, Zhejiang, China Cuifang Zhang Department of Neurosurgery, Ningbo Medical Center Lihuili Hospital, Ningbo, Zhejiang, China Di Gui Department of Pulmonary and Critical Care Medicine, Ningbo Medical Center Lihuili Hospital, Ningbo, Zhejiang, China Hailong Wang Department of Pulmonary and Critical Care Medicine, Ningbo Medical Center Lihuili Hospital, Ningbo, Zhejiang, China 2024 01 09 2024 03 02 The purpose of this study was to systematically examine the association between bronchial asthma and lung cancer. Research on the correlation between bronchial asthma and lung cancer was retrieved from the database. Literature was screened based on inclusion and exclusion criteria, and the number of patients in the included studies was extracted and analyzed. This study used Stata statistical software version 16.0 and Cochrane Review Manager version 5.4 for meta-analysis. In our study, 19 articles were selected. Without considering other influencing factors, the risk of lung cancer in asthma patients was relative risk (RR)=1.40 (95% CI: 1.17-1.67, I2=55.7%), and after correcting for risk factors such as smoking and age, it was found that the risk of small-cell lung cancer in asthma patients was RR=2.11 (95% CI: 1.45-3.24). Asthma may increase the risk of developing lung cancer, with an even higher likelihood for small cell lung cancer. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/3995 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/3995/2088