[The diagnostic significance of biochemical markers.]

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.

Biochemical markers of brain tumours.

The paper presents the results of neurospecific proteins S-100 and glial fibrillary acidic protein (GFAP) determination in blood serum samples of 145 neuro-oncology patients and 69 healthy people. The significant elevation of S-100 and GFAP was revealed in glioblastoma (G IV) patients compare to the patients with anaplastic astrocytoma (G III), benign meningioma (GI), celebral metastasis and healthy controls. The concentration of S-100 in blood serum of patients with anaplastic astrocytoma, benign meningioma, and celebral metastasis did not significantly differ among themselves, and in relation to the control group there was a significantly increase only in patients with cerebral metastasis. GFAP was characterized by high frequency of its detection in patients with glioblastoma (83%) compare to other groups of patients and healthy donors, in which it was practically undetectable. These data suggest the possibility of using GFAP as a marker of glioblastoma and S-100- as an additional biochemical criteria of cerebral lesions in oncology patients.

Neurospecific proteins in the serum of patients with brain tumors.

Neurospecific proteins S-100 and GFAP were measured in the serum of 145 patients with neural tumors and 69 healthy individuals. In patients with glyoblastomas, the concentrations of S-100 and GFAP were significantly higher than in patients with anaplastic astrocytomas, benign meningiomas, and brain metastases and in healthy individuals. Serum S-100 concentrations in patients with anaplastic astrocytomas, benign meningiomas, and brain metastases were similar; significant difference from the control was found only for patients with cerebral metastases. A specific feature of GFAP was high incidence of its detection in patients with glioblastomas (83%) compared to other groups of patients with neural tumors and healthy volunteers who demonstrated practically zero level of this protein. These findings attest to the possibility of using S-100 as an additional biochemical criterion of brain involvement in tumor patients and GFAP as a glioblastoma marker.

Biochemical parameters in the diagnosis and monitoring of neurotoxicity of antitumor cytostatics.

The significance of neurospecific proteins in the diagnosis of neurotoxicity in patients with breast, lung, testicular, and ovarian cancer treated by taxane and cisplatin drugs was evaluated. The most pronounced increase in the content of these proteins and titers of autoantibodies to these proteins was observed in patients with clinical manifestations of neurotoxicity induced by cytostatics. A strong correlation was found between the concentration of myelin basic protein and cumulative dose of the drug (R=0.922; p<0.0001). These data suggest that myelin basic protein and gliofibrillar acid protein can be used as markers in the diagnosis and monitoring of antitumor drug neurotoxicity.