DETERMINATION OF TRACE-ELEMENT DISTRIBUTION IN CANCEROUS AND NORMAL HUMAN TISSUES BY TOTAL-REFLECTION X-RAY-FLUORESCENCE ANALYSIS

The intention of this study was to establish a method for cancer diagn osis. For this purpose, different trace element distributions in carci nomas of the digestive tract and in normal tissues of human stomach, c olon and rectum in correlation to the type of cancer were determined b y total reflection X-ray fluorescence analysis (TXRF). The tissue samp les were frozen and cut by a microtome into 10 mu m sections, and a mo dified sample excision technique was introduced according to the aim o f this research. After drying and spiking of the tissue sections, more than 20 elements, especially biologically relevant ones, were determi ned. The repeatabilities of measurements of element concentrations in malignant and normal tissues were calculated to be 10-30% (RSD) depend ing on the specific element. The concentration of Ca was found to be v irtually constant (0.250 +/- 0.025 mu g per 0.1 mm(3)) in normal tissu e and in carcinoma of the digestive organs. A significant diminution o f Cr, Fe and Ni in carcinoma of the stomach, of Cr and Co in carcinoma of the colon and a significant accumulation of K in cancerous tissue of the colon and of Fe and K in neoplastic tissue of the rectum were d iscovered for a very limited population of patients. (C) 1997 Elsevier Science B.V.