Esophageal cancer (EC) and Gastric cancer (GC) are the eighth and fifth most common cancers worldwide. Golestan province in Northeast of Iran was known as a high risk area for upper gastrointestinal cancers including EC and GC since 1970s. Recent reports suggested decreasing trends in incidence of EC in this region during last decades. We aimed to assess the incidence trends of EC and GC in Golestan province during 15 years, 2004-2018.

Data on cancer incidence if Golestan province during 2004-2018 were obtained from the Golestan population-based Cancer Registry (GPCR). The GPCR is a high-quality cancer registry and is a voting member of the international association of cancer registries (IACR). We calculated age standardized incidence rates (ASR) of EC and GC using the World standard population. The rates were calculated per 100,000 person-year. Estimated annual percent changes (EAPC) and 95% confidence intervals (95%CI) of the ASR were calculated for assessing time trends in the incidence of EC and GC. We also assessed the incidence trends in high- and low-risk regions of esophageal cancer in Golestan province.

Between 2004 and 2018, a total number of 32764 cancer cases were registered in the GPCR, of which 3004 (9.7% of all cancer) and 3553 (10.54%) cases were EC and GC, respectively. The mean (SD) age of EC cases were 65.4 (12.99) years and of which 1688 (56.19 %) were male. The mean (SD) age of GC cases was 64.69 (13.75) years, of which 2438 (68.61%) were male. The ASR (95%CI) of EC and GC were 15.70 (15.13-16.27) and 18.3 (17.67-18.93) per 100000 person-year. The ASR of EC in male and female were 17.84 and 13.62 and those of GC were 25.68 and 11.15 per 100000 person-year, respectively. The ASR of EC in high- and low risk regions were 27.67 and 11.95 per 100000 person-year, respectively. Our findings suggested significant decreasing trends in incidence rates of EC in total population (EAPC= -5.03; 95%CI: -7.78 to -2.19) as well as in male (EAPC=-5.06; 95%CI: -7.65 to -2.40) and female (EAPC= -4.88; 95%CI: -7.83 to-1.83), while there was no significant trend in the incidence rate of GC (EAPC= -1.37; 95%CI: -4.03 to 1.35). We also found significant decreasing trends in the ASR of EC in high- (EAPC=-5.93; 95%CI: -8.00 to -3.82) and low-risk (EAPC= -4.32; 95%CI: -7.49,-1.03) regions with considerably greater changes in the ASR in male population in high-risk region (EAPC=-7.21; 95%CI: -9.11 to -5.27).

Our findings suggested significant decreasing trends for EC rates in total population of Golestan as well as in male and female. We also found significant decreasing trends in the ASR of EC in high- and low-risk regions, with greater decline in high-risk region, especially in male population. Our results showed no significant trend in the ASR of GC. Further studies are warranted to investigate the reasons for time trends in incidence of upper gastrointestinal cancers in this high-risk population.