The article provides data on the study of экпрессии proto-oncogenes expression протоонко-genes with the ICC, N-Myc, Ha-Ras, Ki-Ras and c-Rаf in tumors of the stomach and mucous membranes, taken on the edge of the resection of the body in patients with cancer of the stomach. The control of correctness of use of the applied approach to the analysis of the degree of radical surgical treatment of oncological patients was the molecular-genetic examination of patients with chronic ulcer of the stomach. Violation of the expression of proto-oncogenes captures the mucous membrane of the stomach at a considerable distance from the tumor itself, the morphological transformation of cells is stored in the remaining after resection of the stomach. To assess the effectiveness of surgical treatment of patients with cancer of the stomach expression of oncogenes can be used molecular-genetic analysis of the expression of proto-oncogenes.