Comparative study of plasma chromogranin A levels was carried out in 227 patients with neuroendocrine tumors of various locations and 66 normal subjects, men and women, by standard ELISA. In patients with tumors of all locations (pancreas, stomach, small and large intestine, and lungs), the glycoprotein levels were significantly (p<0.000001) higher than in controls. The patients demonstrated high variability of chromogranin A levels; the maximum concentrations were detected in patients with neuroendocrine tumors of the stomach and lung. The highest median values of chromogranin A were found in patients with tumors of the small intestine, large intestine, and pancreas. A relationship between secretion of chromogranin A and dissemination and activity of the neuroendocrine tumor was detected, which was the maximum in patients with metastases in the liver and carcinoid syndrome. High diagnostic sensitivity of chromogranin A was shown: 85.8% for the total group of patients; specificity was 98.5%. These data confirmed high efficiency of chromogranin A as the marker of neuroendocrine tumors. Detection of this marker promotes more accurate diagnosis and evaluation of dissemination of the neuroendocrine tumors.
Keywords: biochemical marker; chromogranin A; diagnosis; neuroendocrine tumor.