A Systematic Review of the Zinc Content of the Cancerous Human Prostate Gland

摘要

Background : Zinc (Zn) level in prostatic tissue plays an important role in prostatic carcinogenesis and its measurement may be useful as a prostate cancer (PCa) biomarker.Method : The present study evaluated by systematic analysis the published data for Zn content analyzed in cancerous prostates as well as in lateral and dorsal zones of normal glands. This evaluation reviewed 1885 studies, all of which were published in the years from 1921 to 2020 and were located by searching the databases PubMed, Scopus, ELSEVIER-EMBASE, Cochrane Library, and the Web of Science. The articles were analyzed and “Median of Means” and “Range of Means” were used to examine heterogeneity of the measured Zn content in prostates of men with PCa (PCa group) and in prostates of apparently healthy adult subjects (control group). The objective analysis was performed on data from the 57 studies, with 1295 subjects for the PCa group and from the 40 studies, with 1921 subjects for the control group.Results : It was found that the range of means of prostatic Zn content reported in the literature varies widely: for cancerous gland from 3.3 mg/kg to 180 mg/kg with median of means 42 mg/kg and for peripheral zone of normal prostates from 27 mg/kg to 266 mg/kg with median of means 186 mg/kg on a wet mass basis. Ratios of means of Zn content in cancerous prostate (ZnPCa) to Zn content in normal gland (ZnN), both obtained by the same authors and methods, were also calculated.Conclusion : Because of the uncertainties we have outlined, we recommend other primary studies should be performed.