Evaluation of selected microelements concentrations in plasma of colorectal carcinoma patients.

Dietary or pathological antioxidant deficiencies, including those of zinc (Zn) and selenium (Se), impair the protective system of the organism against free oxygen radicals. Iron (Fe) and copper (Cu) may in turn act as prooxidants. Induction of neoplasmic changes, leading to the colorectal carcinoma (CC), is a frequent result of these disturbances. The aim of the study was to evaluate Zn, Se, Fe and Cu concentrations in the plasma of patients with two advancement stages of CC. The study involved four adult groups: I - 20 healthy, II - 15 ill with colorectal adenoma (as a precancerous condition), III - 23 ill with operative CC, IV - 13 ill with non-operative CC. Analyses were performed in plasma using AES-ICP method. Concentrations of Zn and Se were the most decreased, both in II and III-IV groups (p<0.01). Reduction of Fe and Cu concentrations was lower, but also significant (p<0.05). The studies show the decrease of antioxidative potential which may be influenced by the uptake of Zn and Se from plasma to protect the large bowel affected with CC. The decreases of Fe and Cu concentrations may result from internal haemorrhages in CC. The results suggest the necessity of considering foodstuffs delivering Zn and Se to a diet as a prevention factor of CC and also advisability of supplementation with these microelements in deficiency conditions.