Copper and Zinc levels in normal and malignant tissues

TLDR

The study proposes that elevated tissue copper levels may contribute to malignant transformation through free‑radical–induced biological damage. Copper and zinc concentrations were quantified in 53 malignant and 47 normal human tissue samples. Malignant tissues exhibited a 46% higher mean copper level (significant in large bowel, stomach, urinary bladder, and female reproductive organs but not in breast, kidney, or testis), while zinc levels were largely unchanged except for a 72% increase in breast cancer and a 73% decrease in kidney carcinoma.

Abstract

The copper and zinc levels in 53 malignant and 47 normal human tissue samples were measured. In the malignant tissues, the mean copper concentration was 46% higher (P less than 0.001) than in the normal ones. Analysis of the individual organs showed this increment to be statistically significant in malignancies of the large bowel, stomach, urinary bladder and female reproductive organs, while in cancer of the breast, kidney and testis, the increase in copper level was not significant. The mean zinc concentration in the malignant tissues was not significantly different from that in the corresponding normal tissue specimens (-11%; P less than 0.2). In breast cancer, however, tissue zinc levels were increased by 72% (P less than 0.01), and decreased markedly in carcinoma of the kidney (-73%). A hypothesis for the possible mechanism involving elevated tissue copper levels in biological damage (previously caused by free radicals) which may be responsible for the malignant process, is presented and discussed.