Abstract
Introduction Earlier studies showed considerable urban-rural variations in both the incidence of and survival form gastric cancer in Russia. However, the factors behind this association remain unknown. We studied whether these differences can be explained by earlier diagnosis or better accessibility of treatment to urban patients using the data from the Arkhangelsk Regional Cancer Registry (ARCR). Methods Data on all cases of GC in 2000–2012 were obtained from ARCR. Information on stage at diagnosis, histology, gender, age, year of diagnosis, as well as treatment was collected. One and five year survival was estimated using life tables method Cox regression was used to study associations between the residence and survival by consecutive introduction of independent variables into the model. Hazard ratios (HR) with 95% confidence intervals (CI) were calculated. Results Altogether there were 7098 cases of gastric cancer registered in the ARCR in 2000–1012. One- and five years survival in urban areas were 0.40 (95% CI: 0.39-0.42) and 0.21 (95% CI: 0.20-0.22). The corresponding numbers for the rural areas were 0.35 (95% CI: 0.33-0.37) and 0.16 (95% CI: 0.15-0.17). Urban residents had better overall survival in crude analysis (HR = 0.81, 95% CI: 0.76-0.85). Adjustment for stage of diseases reduced this association to HR = 0.90 (95%CI: 0.85-0.96). Adjustment for all other factors did not alleviate the association (HR = 0.92, 95% CI: 0.85-0.98). Conclusions Survival of GC patients from urban areas was substantially better compared to their rural counterparts. Although urban residents were often diagnosed with GC earlier stage, it could not fully explain urban-rural differences in survival from GC suggesting that other factors, particularly, social deprivation might also contribute to the observed variations by place of residence. Key messages Survival of GC patients from urban areas was substantially better compared to their rural counterparts Earlier diagnostics cannot explain the observed variations