The available classifications of malignant tumors reflect various aspects of their
growth and some biological features. The most commonly used in Ukraine is the 6-th revision of TNM
classification, which differs from the previous classifications of the section "Gastric cancer", mainly
staging of category N, reflecting the presence of metastases in regional lymph nodes. Transition to the
7-th classification of TNM translates a part of patients from one stage to another, there is a so-called
"stage migration" phenomenon. The famous mathematical phenomenon of Will Rogers describes this
transition and theoretically substantiates its objectivity. The authors tracked the migration of patients
and the change in the stage mainly from the point of view of the effect of this event on the survival of
patients with stomach cancer
