Plasma and cancerous tissue concentrations of Zn, Cu and Mn in patients undergoing surgical treatment for gastrointestinal cancer

Gastrointestinal cancers have a complex and multifactorial etiology and their immediate cause remains to be discovered. Elements such as zinc, copper or manganese, which are important components of antioxidant enzymes, may affect malignant processes. The objective of this study was to determine zinc, copper and manganese concentrations in the blood, cancerous and healthy control tissue of patients operated on for gastrointestinal malignancies as well as to assess the effect of surgical removal of the tumour on the concentration of these elements. The study included 68 patients who underwent surgery for gastrointestinal cancers. Patients were divided into three groups according to tumour location: group I – oesophageal cancer, group II – gastric cancer and group III – colorectal cancer. Study material consisted of venous blood samples obtained from patients before the surgery and on the seventh day after the surgery; tissue samples were taken during the surgery. The study has demonstrated that the malignant disease process causes changes in trace element status both in plasma and in cancerous tissues. Copper concentrations were elevated both in patients’ plasma and in cancerous tissues, while a decrease was observed in zinc and manganese concentrations in comparison with control tissue. The surgery affected levels of these elements to various degrees corresponding to the location of removed tumour.