Introduction: The modern diagnostic of neuroendocrine tumors is based on analysis of compounds produced by tumor cells (peptides, amines, hormones).
Purpose of study: To evaluate diagnostic effectiveness of Chromogranin A, serotonin and its metabolite 5-hydroxyindolilacetic acid as biochemical markers of neuroendocrine tumors as biochemical markers of neuroendocrine tumors.
Material and methods: The detection of Chromogranin A and serotonin in blood serum and 5-hydroxyindolilacetic acid in day urine was applied to 330 patients with neuroendocrine tumors of lungs, pancreas, stomach, small and large intestines and also to 115 healthy males and females. The detection was implemented by enzyme-linked immunosorbent assay based on testsystems "Chromogranin A ELISA Kit" (Dako A/S, Denmark), "Serotonin ELISA" and 5-HIAA ELISA (IBL International GMBH, Germany).
Results and discussion: The levels of Chromogranin A at all localizations of neuroendocrine tumors reliably (p<0.000001) exceeded corresponding control index. In case of serotonin and 5-hydroxyindolilacetic acid reliable differences were established in all groups except neuroendocrine tumors of stomach. The dependence is established between secretion of markers from prevalence and activity of neuroendocrine tumors. The corresponding levels were higher in patients with metastases in liver and under carcinoid syndrome as compared with patients without corresponding clinical manifestations. The evaluation of diagnostic significance of Chromogranin A, serotonin and 5-hydroxyindolilacetic acid was applied considering threshold levels calculated according results of their detection in control group (33 ng/ml, 320 ng/ml and 60 mkmol/day correspondingly). The high diagnostic sensitivity of Chromogranin A was demonstrated that amounted to 80.6% at specificity 98.5% on the whole in group of patients with neuroendocrine tumors. The serotonin and 5-hydroxyindolilacetic acid manifested comparable diagnostic sensitivity only in patients with carcinoid syndrome (72.5 and 60.3%).
Conclusion: The obtained data substantiate high effectiveness of Chromogranin A as a marker of neuroendocrine tumors. The detection of this marker contributes into enhancement of accuracy of diagnostic and evaluation of prevalence of tumors of neuroendocrine nature. The serotonin and 5-hydroxyindolilacetic acid are markers of carcinoid syndrome.
Keywords: 5-hydroxyindolilacetic acid; Chromogranin A; biochemical marker; carcinoid syndrome; diagnostic; neuroendocrine tumor; serotonin.