Abstract 1920: Association of type 2 diabetes with overall and site-specific cancer among predominantly low-income Black and White Americans

Background: Black individuals have the highest cancer incidence rate in the United States compared to White and other populations. Additionally, they are also twice as likely to develop type 2 diabetes (T2D) during their lifetime. Specifically considering the association between diabetes and cancer incidence, both diseases share common modifiable and nonmodifiable risk factors such as, aging, obesity, lack of physical activity, unhealthy diet, excessive alcohol consumption, and smoking. This association could vary between cancer types and race is also a factor which could disproportionately affect this relationship. However, studies on these associations are limited and the impact in terms of risk between the Black and White Americans remains unclear. Objective: We evaluated the association of T2D with risk of total and 26 site-specific cancers in a large cohort study conducted among predominantly low-income Black and White Americans who have a higher risk of T2D than other populations. Given the previous literature on T2D, cancer, and race, we hypothesized that T2D might be associated with varying risk for cancer. Methods: For this analysis, we used data from the Southern Community Cohort Study, an on-going prospective cohort study. Enrollment began in 2002 and concluded in 2009, with active follow-up until 2020. Study participants were asked whether they were diagnosed with T2D by physicians at the follow-up interviews and T2D was assessed as a time-varying covariate. Ascertainment of incident cancer was carried out via linkage to state cancer registries. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) after adjusting for confounders. Results: This study included 81,525 participants (30.2 % (N=24,581) White; 65.9% (N=53,711) Black) of whom 36.2% (N=29,487) were diagnosed with diabetes. Among those with diabetes, 10.3% (N=3,024) were diagnosed with cancer. Individuals with T2D had an elevated risk of several cancers, including pancreatic cancer (HR = 1.52, 95% CI: 1.18-1.96); but a reduced risk of esophageal cancer (HR = 0.55, 95% CI: 0.34-0.89). Some racial differences were found regarding the association of T2D with cancer risk. Conclusion: We found varying risks between T2D and risk of cancer between White and Black individuals. This highlights the importance of T2D prevention practices to help mitigate the risk of cancer and that further research is necessary to understand this association in