Background:Previous studies have reported the association of an insertion/deletion (Ins/Del) polymorphism (rs145204276 AGGCA/-) in the promoter region of growth arrest-specific 5 (GAS5) with the risk of cancer, such as breast cancer, gastric cancer, and hepatocellular carcinoma. However, the results are still controversial. We aimed to clarify the association of GAS5 rs145204276 polymorphism with cancer risk by meta-analysis.Methods:PubMed, Embase, Web of Science, China National Knowledge Infrastructure, Wanfang, and Cochrane Library were searched for studies concerning GAS5 and cancer published up to November 25, 2019. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate cancer risk.Results:A total of 12 case–control studies with 8729 cases and 10,807 controls were included in this meta-analysis. We found that the GAS5 rs145204276 polymorphism was not significantly associated with cancer risk (Del vs Ins: OR = 0.96, 95% CI: 0.81–1.13; Del/Del vs Ins/Ins: OR = 1.00, 95% CI: 0.70–1.43; Ins/Del vs Ins/Ins: OR = 0.92, 95% CI: 0.78–1.08; Ins/Del and Del/Del vs Ins/Ins: OR = 0.93, 95% CI: 0.76–1.13; Del/Del vs Ins/Del and Ins/Ins: OR = 1.04, 95% CI: 0.78–1.38). In the stratified analyses, significant effects on gastric cancer were found (Del vs Ins: OR = 0.79, 95% CI: 0.72–0.86; Del/Del vs Ins/Ins: OR = 0.65, 95% CI: 0.52–0.82; Ins/Del vs Ins/Ins: OR = 0.76, 95% CI: 0.68–0.86; Ins/Del + Del/Del vs Ins/Ins: OR = 0.74, 95% CI: 0.66–0.83; Del/Del vs Ins/Ins + Ins/Del: OR = 0.74, 95% CI: 0.59–0.91).Conclusion:Our meta-analysis showed that GAS5 rs145204276 polymorphisms were not related to overall cancer risk. However, the GAS5 rs145204276 polymorphism may be a protective factor for gastric cancer in the stratification analyses.