The relationship between exposure to cadmium and the risk of prostate cancer: a systematic review and meta-analysis

Background. Prostate cancer is the second most common cancer in men and the fifth leading cause of death worldwide. Our aim in this study was to investigate the relationship between exposure to cadmium and the incidence of prostate cancer through conducting a systematic review and meta-analysis method. Methods. The Studies that investigated the relationship between cadmium and prostate cancer were searched and retrieved from the international databases until May 2022. (x2) and (I2) statistical tests were used respectively to determine the presence and size of heterogeneity; Egger's and Bagg's tests were used to determine the existence of diffusion bias; and meta-regression and sensitivity analysis were used to identify the source of heterogeneity. All analyses were performed by Stata (Version 15) statistical software. Results. It was observed that the relative risk of prostate cancer occurrence compared to the base group, in people exposed/exposed to a dose higher than the base level was equal to 1.05(95% CI:0.94-1.17; P=0.372); Meanwhile, no statistically significant relationship was observed between exposure to cadmium or exposure levels exceeding the baseline and prostate cancer. According to the results of Egger's test (P = 0.989) and Begg's (P= 0.787), diffusion distortion was not observed in this study. Conclusion. Based on the available evidence, although exposure to cadmium leads to an increase in the risk of prostate cancer, this risk increase is not statistically significant. Practical Implications. The World Health Organization should think with a more serious approach to the relationship between environmental health and cancers.