The aim was to identify cytogenetic disorders, proliferative activity and apoptosis in cells exfoliated buccal and nasal epithelium in patients with gastric cancer. The study involved 10 patients with an established diagnosis. The control group included 30 healthy people. It has been revealed that all this parameters were increased in buccal and nasal epithelium in patients with gastric cancer than in healthy people. The detected changes are systemic in nature and reflect the overall condition of the body. Moreover, we show reduction of karyological parameters after radical treatment, which indicates their prognostic significance.