Multielement analysis in serum of thyroid cancer patients before and after a surgical operation.

Concentrations of trace elements Zn, Cu, Fe, Mn, Mg, and Sr in the serum of 50 thyroid cancer patients and 50 healthy controls were analyzed comprehensively by Pattern Recognition Analysis Method. Based on the Principal Component Analysis Method, Zn, Cu, and Sr were found to be the principal elements with significant variations between patients and healthy controls. According to the Mahalanolis Distance Decision and Nonlinear Mapping Methods, the trace elements levels in the serum of cancerous patients were found significantly different from that of controls. For 16 thyroid malignant tumor patients who underwent surgery, sample points of patients after surgery were directional away from corresponding points before surgery. However, an overlapping was found and separation between two groups of points was not complete. This finding suggests that there may be a latency period for the restoration of trace element levels after removal of the malignant tumorous tissue.