Survival of Stomach Cancer Patients in Western Kazakhstan: a Registry-Based Study

Abstract

Introduction: Stomach cancer is the fourth most common cancer worldwide. Although there is a lot of international evidence on survival of stomach cancer patients, the data from Central Asia is still scarce. Aims: To study one- and five-years survival of stomach cancer patients and its correlates in Western Kazakhstan. Methods: All histologically confirmed cases of stomach cancer (ICD10 code: C16) registered from 2015 to 2019 in the Aktobe region, Western Kazakhstan, were included in a registry-based historical cohort study. One- and five-years survival with 95 % confidence intervals (CI) was calculated by life tables method. Independent associations between survival and its correlates were studied using Cox regression and presented as crude and adjusted hazard ratios (HR). Results: Altogether, there were 793 new cases of and 587 deaths from stomach cancer in the Aktobe region over the study period. Sixty-five percent of cases were diagnosed at stage III or IV. The overall one- and five-year survival was 33.1 % and 8.4 %, respectively. Significant differences in survival functions across categories were observed for cancer stage (p < 0.001), morphological type (p < 0.001) and ethnic background (p = 0.017). After adjustment, only stage and morphological type of tumor remained significantly associated with the out come. Stage III (HR = 2.3, 95 % CI: 1.5-3.6) and stage IV (HR = 4.4, 95 % CI: 2.8-6.9) were associated with shorter survival compared to the reference category. Patients with intestinal type of cancer were more likely to survive longer (HR = 0.7, 95 % CI: 0.6-0.8). Conclusions: High proportion of cases diagnosed at advance stage and low survival warrant urgent measures on both population and institutional levels. Preventive activities, increased awareness of the population and implementation of routine screening should be among the priority actions to improve survival of stomach cancer patients and decrease cancer mortality in Western Kazakhstan.