The Association Between Gastroesophageal Reflux Disease and Lung Cancer: A Systematic Review and Meta Analysis

Background: Gastroesophageal reflux disease (GERD) is a common problem that affects patients. The constant irritation of the esophageal mucosa, in addition to the potential aspiration, has been suggested as a predisposing factor for lung cancer (LC). This study aims to investigate the association between GERD and LC. Methods: An electronic search was conducted on EMBASE, CENTRAL, and PubMed databases from inception through November 2025. Studies evaluating the association between GERD and lung cancer in adult populations were included. Reviews, non-English articles, pediatric studies, and non-human studies were excluded. Twelve studies involving 2,900,965 patients met the inclusion criteria. Three types of common and random effect meta-analyses were utilized, namely meta-analysis of proportion, log(HR) and log(OR) models. Included studies were examined for risk of bias using the Newcastle-Ottawa scale. Results: Twelve articles describing 2,900,965 patients were found to be fit for inclusion. Male and female sexes were equally represented. On average, patients were 57.67 ± 10.02 years of age. Pooled proportion of co-occurring LC and GERD in patients was estimated at 64% [95% C.I.: 15-95%; p = 0.02], with significant heterogeneity (I² = 96.8%, p < 0.01). Among studies calculating for hazard ratio (HR), an estimated pooled log(HR) of 1.01 [95% C.I.: 0.36-2.8; p = 0.98] with significant data heterogeneity (I² = 88%, p < 0.01) was found. In comparison, five studies included estimates of odds ratio (OR), which resulted in a pooled log(OR) of 1.32 [95% C.I.: 1.2-1.46; p < 0.01], with less heterogeneity (I² = 59.1%) which was marginally significant (p = 0.04). Conclusions: Our findings may suggest a possible association between LC and GERD; however, estimates were discordant across effect measures and heterogeneity was substantial, so this association should be interpreted with caution.