Scientists Link Type 2 Diabetes to Increased Risk of Certain Obesity-Related Cancers

London: A fresh diagnosis of type 2 diabetes (T2D) may significantly raise the risk of developing certain obesity-related cancers (ORCs), according to a new study to be presented at the upcoming European Congress on Obesity (ECO 2025) in Malaga, Spain.

While previous studies have noted an association between T2D and elevated risk of several obesity-related cancers, concerns remained about whether these links were truly causal or influenced by shared risk factors like obesity, biases in study design, or timing of diagnosis. To address these gaps, researchers conducted a rigorous matched cohort study using data from the UK Biobank, focusing solely on individuals with newly diagnosed T2D.

In the study, 23,750 participants with new-onset type 2 diabetes were compared to 71,123 individuals without diabetes, matched by body mass index (BMI), age, and sex. Over a median follow-up of five years, researchers documented 2,431 new cases of primary cancer among T2D participants, compared to 5,184 cases in the control group.

The analysis revealed a marked increase in cancer risk linked to T2D. Men with newly diagnosed diabetes faced a 48% higher risk of developing obesity-related cancers, while women saw a 24% increased risk—findings that were independent of BMI. However, not all obesity-related cancers showed this association. For instance, no significant link was found between new-onset T2D and the risk of endometrial or postmenopausal breast cancer in women.

Site-specific analysis highlighted certain cancers where the association was particularly strong. Bowel cancer risk rose by 27% in men and 34% in women with new-onset diabetes. Pancreatic cancer risk surged by 74% in men and nearly doubled in women. Most strikingly, liver cancer risk almost quadrupled in men and increased nearly five-fold in women with T2D.

The researchers noted that it remains unclear why these risks differ between sexes, suggesting possible influences like hormone levels, insulin sensitivity, fat distribution, or random variations in cancer incidence between men and women in the UK Biobank data.

These findings emphasize the importance of cancer surveillance and risk management in individuals newly diagnosed with type 2 diabetes.