Plasma copper and zinc levels in patients with malignant tumors of digestive organs: clinical evaluation of the C1/Zn ratio.

The plasma copper level (PCL) and plasma zinc level (PZL) were determined in 126 patients: 54 had carcinomas of which 40 were carcinomas of the digestive organs, 37 had benign lesions, and 35 were without disease. The PCL increased and the PZL decreased significantly in the group with carcinoma of the digestive organs. The CuHZn ratio was not only significantly higher than in the normal group, but also was high in cases with advanced carcinoma especially when liver metastasis was present. Therefore, the Cu/Zn ratio may be valuable in estimating the extent of the carcinoma as well as in determining the prognosis of the cancer patients.