Background. In advanced gastric cancer (GC), the main method of treatment is antitumor drug therapy. However, the progno-
sis for stage IV gastric cancer remains unfavorable, and therefore interest in the combination of chemotherapy with surgery
is renewed.
Influence of palliative gastrectomy on the survival of patients with stage IV gastric cancer. The role of palliative gastrectomy in stage IV gastric cancer has been evaluated in a number of retrospective analyzes with conflicting results. The results of the REGATTA study showed that palliative gastrectomy followed by chemotherapy did not improve patient survival. There is an ongoing debate about the impact of palliative gastrectomy on survival rate in the literature.
Influence of conversion therapy on the survival of patients with stage IV gastric cancer. The term “conversion therapy” reflects a treatment concept with the effect of antitumor therapy on initially inoperable disseminated process to transferd to a resectable
state with the possibility of complete surgical removal of tumor. The article presents a thematic review of studies; almost of them
were retrospective. According to the prospective phase III study Neo-REGATTA, the survival rate of patients who received
conversion therapy was significantly (P<0.0001) higher than in the chemotherapy group. According to the results of meta-analyzes, the optimal strategy for the treatment of patients with stage IV gastric cancer is a combination of chemotherapy followed by surgery.
Conversion therapy: prognostic factors. As a result of multivariate Cox-analyses conducted by different authors, the following prognostic factors were identified: 1) satisfactory functional patient status ECOG 0-1; 2) performing R0 surgery; 3) the presence of only the one zone of distant metastasis; 4) chemotherapy at the first step of treatment; 5) achieving an objective effect of chemotherapy by the time of surgery; 6) at least 6–8 courses of chemotherapy before surgery.
Selection criteria for conversion therapy. Taking into account the heterogeneity, different biology and prevalence of the tumor, it is proposed to divide patients with stage IV gastric cancer into 4 categories: 1) patients with a potentially resectable process without peritoneal metastases; 2) patients with a borderline operable process without peritoneal metastases; 3) patients with macroscopically defined peritoneal dissemination, but without other distant metastases; 4) patients with macroscopically detectable peritoneal metastases and other distant metastases. Patients of the 1st and 2nd categories, less often – the 3rd and single patients of the 4th category can be considered as candidates for conversion. A critical analysis of the classification and the results of its practical application are presented.
Conclusion. To determine the role of the surgical method in the treatment of patients with stage IV gastric cancer, randomized prospective studies are required.

Keywords: oligometastatic disease, conversion surgery, conversion therapy, chemotherapy, gastric cancer