Abstract
Background/Objectives: Cancer incidence and mortality are key epidemiological indicators for evaluating the long-term biological effects of chronic low-dose radiation exposure. The aim of this study was to assess the incidence, structure, and relative risk of digestive tract cancers (ICD-10 C15–C26) among populations exposed and not exposed from uranium waste storage site in North Kazakhstan over a 10-year period (2014–2023). Methods: A retrospective population-based analysis was conducted using national cancer registry data, including data for residents of Stepnogorsk and nearby settlements (exposed group) and Akkol (control group). Results: A total of 588 cases were identified, including 465 in the exposed group and 123 in the control group. The mean age at diagnosis was similar (~65 years), and most cases were diagnosed at advanced stages (III–IV: ~58–60%). The leading cancer types were colorectal (38–40%) and stomach (29–31%) in both groups. The incidence rates were comparable (85.27 vs. 87.40 per 100,000), with an overall relative risk (RR) of 0.98 (95% confidence interval [CI]: 0.80–1.19), indicating no significant difference. Site-specific analysis showed no significant variation for esophageal, stomach, or colorectal cancers. A higher, but not statistically significant, risk was observed for pancreatic cancer (RR = 1.61; 95% CI: 0.90–2.89). Temporal analysis demonstrated similar trends in both populations, with incidence rates decreasing from 91.37 to 79.08 per 100,000 in the exposed group and from 97.40 to 78.13 per 100,000 in the control group between 2014–2018 and 2019–2023. Conclusions: Overall, digestive tract cancer incidence and structure were comparable between groups, with no statistically significant increase in the exposed population.