Background — With continued improvements in survival following childhood cancer, the long- term health consequences of cancer treatments are receiving greater focus. Diabetes is emerging as a potential late-effect of cancer therapy; however, the magnitude of risk has not been well established given limited studies. The goal of our study was to evaluate the risk of diabetes in childhood cancer survivors using validated population-based databases.
Materials and Methods — We used the Ontario Cancer Registry linked to provincial administrative health databases to compare the rate of diabetes in survivors of childhood cancer compared with the general population in Ontario. Diabetes was measured using a validated algorithm. We used a multivariable, cause-specific hazard regression model where death and development of another cancer was treated as a competing risk.
Results — We identified 10,438 1-year survivors of childhood cancer diagnosed prior to age 21 years between January 1st, 1990 and December 31st, 2010. The mean follow up was 11.2 (standard deviation [SD] 6.9) years. Cancer survivors had a 55% increased rate of developing diabetes compared to matched controls (HR 1.51, 95% CI 1.28-1.78) in models adjusted for rurality and income. Individuals treated for cancer between 6-10 years old had the highest increased rate for diabetes (HR 3.89, 2.26-6.68). Among cancer types, leukemia and lymphoma were associated with the greatest increased risk for diabetes.
Conclusions — Our study supports evidence of an increased risk for diabetes in childhood cancer survivors. Future research is warranted to better identify treatment-related and non-traditional risk factors for diabetes in this population.