Comparative study of zinc levels in benign and malignant lesions of the prostate

The normal human prostate accumulates the highest levels of zinc of any soft tissue in the body. The presence of zinc in the prostate of a number of mammalian species, including rhesus monkeys and humans, has been well documented. The aims of this study were to investigate the concentrations of zinc in various disorders of the prostate and to find a correlation between them.

A total of 80 cases were studied (20 normal, 50 benign, 10 carcinomatous). A plasma sample was taken and zinc levels were analyzed using atomic absorption spectrophotometry.

The mean (+/-SD) plasma zinc level in the normal cases was 94.5+/-10.38 microg/100 ml. Amongst patients with benign diseases of the prostate gland, the plasma zinc level was 145.4+/-9.67, 162.4+/-2.22 and 172.7+/-5.27 microg/100 ml (78% rise compared to normal patients) in those with a fibromuscular prostate, chronic prostatitis and benign prostatic hyperplasia, respectively, whilst patients with malignancy had a plasma zinc level of 59.6+/-3.08 microg/100 ml (37% fall compared to normal patients). There was a highly statistically significant (p < 0.01) difference in plasma zinc levels between patients with benign and malignant prostate diseases. The effect of metastasis of carcinoma of the prostate on plasma zinc levels was not significant (p > 0.05), while there was a highly statistically significant (p < 0.01) correlation between serum prostate-specific antigen and plasma zinc levels in malignancy.

There appears to be a strong correlation between plasma zinc levels and various prostatic diseases. Therefore, the determination of zinc levels can be used as a diagnostic or screening tool and may lead to the formulation of methods in which zinc is used to evaluate prostatic pathology.