Use of the serum copper/zinc ratio in the differential diagnosis of ovarian malignancy.

We measured copper and zinc in serum (n = 82) and tumor tissue (n = 41) from women with a palpable pelvic mass, admitted for suspected ovarian tumor. In serum, copper was increased and zinc decreased in the group (n = 40) subsequently proven to have a malignant ovarian tumor. The mean copper/zinc ratio in this group was 2.30 (SD 0.41), significantly (p less than 0.001) higher than for the benign group (n = 42), 1.43 (SD 0.22). In tumor tissue the concentrations of copper and zinc followed the same pattern, the copper/zinc ratio being significantly (p less than 0.001) higher in the malignant (0.158, SD 0.065) tumors than in the benign tissue (0.093, SD 0.04). We conclude that the Cu/Zn ratio in serum reliably (specifically) indicates the presence of advanced ovarian malignant tumor. The decreased concentrations of zinc and the increased concentrations of copper in serum do not seem to result from a shift of zinc into or release of copper out of the malignant tumor tissue.