Investigating the Relationship Between Exposure to Cadmium and Lung Cancer Risk: A Systematic Review and Meta-analysis

Abstract

Introduction: Lung cancer is the second most common cancer in the world. Smoking occupational and environmental exposures are the most important causes of lung cancer. Cadmium is known as a human carcinogen due to its ability to increase lung cancer risk. This study estimates the general results of all studies on the relationship between cadmium and lung cancer. Material and Methods: In the present study, studies that evaluated the relationship between cadmium and lung cancer until May 2022 were searched and retrieved. From the funnel plot to determine the existence of diffusion skew, from the statistical tests Chi-squared test (x2) and I2 to determine heterogeneity, from the meta-regression method to identify the root of heterogeneity, and from the sensitivity analysis approach to identify the effect of each study on the result, it was generally used. This study performed all analyses with Stata statistical software version 15. Results: In this study, it was observed that the chance of developing lung cancer compared to the base group, in the people exposed to a higher dose than the base level of cadmium is equal to 1.31 (95% CI: 1.06-1.62; p-value = 0.024), which is statistically significant. Based on Egger’s test (p-value = 0.178) and Begg’s (p-value = 0.276), no diffusion bias was observed in this study. Conclusion: ccording to the final results of this review research, exposure to cadmium leads to a 31% increase in lung cancer risk, which is statistically significant. Therefore, cadmium is a risk factor for lung cancer.

Keywords

• systematic review
• meta-analysis
• odds ratio
• lung cancer
• cadmium