[Possibilities of early diagnosis of tumors]

To study diagnostic significance of blood serum cancer antigens levels in patients who subsequently develop pulmonary cancer (PC) and gastrointestinal cancer (GIC).

ELISA was used to study expression of tumor antigens (CEA, NSE, CA19-9, CA242, AFP) in the blood serum of 27 PC and 31 GIC patients; 22 patients with lymphatic tumors and 32 patients with pulmonary and gastrointestinal inflammation served control. After removal of the tumor the same antigens including cytokeratines (CK) and differentiated leukocytic markers were studied immunocytochemically in the tumor cells with relevant monoclonal antibodies.

Sera of patients with verified afterwards cancer contained elevated concentrations of the antigens: NSE and CEA in PC, CA19-9, CA242 in GIC. The expression of these antigens including CK was found also in tumor cells of these patients. Atypical cells of lymphatic tumors had hemopoietic markers in the absence of CK. In inflammation and in lymphatic tumors, tumor antigens levels remained normal.

The test for tumor antigens levels in the serum may be used for early (preoperative) diagnosis of cancer, especially in tumors with difficult access or if they are asymptomatic.