Age at type 2 diabetes diagnosis and risk of cancer: Cohort study in over 1 million individuals from the TriNetX US Collaborative Network.

<h4>Aims</h4><p dir="ltr">To investigate whether the association between type 2 diabetes diagnosis and relative and absolute risk of obesity-related cancers differs based on age at diabetes diagnosis.</p><p dir="ltr">Methods</p><p dir="ltr">This retrospective, observational cohort study used data from the US Collaborative Network within the TriNetX database. Individuals with type 2 diabetes were propensity matched – for age, sex, and ethnicity – to individuals without type 2 diabetes. Crude 5-year risks of obesity-related cancer were calculated. Cox proportional-hazards models were used to assess relative rates of obesity-related cancer incidence over five years, comparing individuals with type 2 diabetes in younger (aged ≤40 years; n = 162,691) and middle-older age (aged >40 years; n = 1,616,950), with propensity-matched cohorts without type 2 diabetes.</p><p dir="ltr">Results</p><p dir="ltr">Absolute risk of developing cancer was greater in individuals with versus without type 2 diabetes. Relative rates of any cancer were greater in younger (HR: 2·01 [95 % CI: 1·85, 2·19]) than middle-older age adults (1·49 [1·48, 1·51]). The highest relative rates in younger adults were observed for corpus uteri (HR: 4·76 [3·51, 6·46]) and pancreatic cancer (4·25 [2·34, 7·72]). Corresponding HRs in middle-older age adults were 1·92 (1·84, 2·01) and 1·75 (1·68, 1·83).</p><p dir="ltr">Conclusions</p><p dir="ltr">The five-year risk of cancer was higher in those with newly diagnosed type 2 diabetes versus those without. Absolute risk was greater in middle-older age adults, although relative rates were greater amongst younger adults. This persisted across most site-specific cancers, suggesting targeted strategies for early detection and prevention may help younger adults with newly-diagnosed type 2 diabetes reduce lifetime disease burden.</p>