London: A new diagnosis of type 2 diabetes (T2D) has been linked to a subsequent increase in the risk of developing some, but not all, obesity related cancers, according to new research.
Previous research has described associations between type 2 diabetes mellitus and higher risk of several obesity-related cancers.
However, it remains unclear whether these associations are causal, due to confounding (their mutual risk factor of obesity); immortal time bias (many studies combine prevalent and new-onset T2D); or time detection bias (for example, the co-diagnosis of two relatively common conditions at the same time).
In this study, to be presented at European Congress on Obesity (ECO 2025, Malaga, Spain, 11-14 May), the authors aimed to address these previous methodological flaws.
They performed a matched cohort control study within UK Biobank of new-onset T2D (defined by date of first reported non-insulin dependent diabetes) versus unexposed individuals matched (1 participant to 3 controls) on body mass index (BMI), age, and sex.
A total of 23,750 participants with T2D were matched with 71,123 controls. Over a median follow-up time of 5 years, there were 2431 new primary cancers among T2D participants and 5184 new primary cancers among matched controls.
The data analysis showed new-onset T2D was associated with a 48 per cent increased risk of obesity related cancers in men and a 24 per cent increased risk in women – an effect independent of BMI. However, there were no associations with several site-specific ORCs – notably, endometrial, and post-menopausal breast cancer in women
There were positive associations found – new onset T2D increased the risk for bowel cancer by 27 per cent in men and 34 per cent in women; for pancreatic cancer by 74 per cent in men and a near-doubling of risk in women. For liver cancer new onset T2D was associated with a near-quadrupling of risk in men and near 5-fold increased risk in women.
“At this stage, we are unsure whether these differences in men and women are due to a sex-dependent biological pathway such as hormone levels, insulin sensitivity, body fat composition, or due to a simple difference in the number of cancers found in men and women within UK Biobank by chance,” said the study authors.
