Adults with type 2 diabetes develop cancer more frequently than the general population, and the gap between the two groups has widened steadily over the last three decades, according to a major 27-year study from Aarhus University Hospital in Denmark.
Researchers analyzing data across the entire Danish adult population between 1996 and 2022 found that global cancer incidence between 2010 and 2022 was 12 percent higher in men with type 2 diabetes and 22 percent higher in women with type 2 diabetes compared to those without the condition. In the earlier 1996 to 2009 period, the differences were lower, standing at 9 percent for men and 15 percent for women.
The findings were presented at the Annual Meeting of the European Association for the Study of Diabetes. Lead author Tinne Laurberg, of the Steno Diabetes Center Aarhus, said the results underline a growing cancer burden among people with type 2 diabetes and highlight the urgent need to prioritize cancer prevention and early detection during routine long-term medical care.
Type 2 diabetes is a chronic metabolic condition characterized by high blood sugar levels resulting from the body producing insufficient insulin or becoming resistant to its effects. The European Association for the Study of Diabetes is an international medical organization dedicated to advancing research and improving patient care, while Aarhus University Hospital is a major Danish clinical research institution.
Sharper increase in obesity-related tumors
The study focused closely on tumors linked to obesity, such as colorectal cancer and postmenopausal breast cancer, for which screening programs already exist in many countries. Authors of the paper emphasized that patients with type 2 diabetes should benefit fully from these screening strategies given their elevated and rising risk.
Across the entire 27-year observation period, investigators identified 75,540 first cancer diagnoses among individuals with type 2 diabetes and 635,323 first cancer diagnoses among adults without diabetes. The divergence was particularly pronounced for obesity-related tumors. Between 2010 and 2022, the incidence of these specific tumors was 45 percent higher in men with type 2 diabetes and 30 percent higher in women with type 2 diabetes. During the 1996 to 2009 timeframe, those figures stood at 34 percent and 23 percent respectively.
Postmenopausal breast cancer in women with type 2 diabetes showed an incidence 8 percent higher in the recent 2010 to 2022 period. Colorectal cancer, which ranks as the third most common cancer worldwide, recorded a 17 percent increase in men with type 2 diabetes and a 14 percent increase in women with type 2 diabetes relative to adults without the metabolic disease.
Obesity is a well-established risk factor for several malignancies, as excess adipose tissue can drive chronic systemic inflammation, alter hormone production, and elevate circulating insulin levels. Routine screening programs, including regular mammograms for breast cancer and colonoscopies for colorectal cancer, are standard preventative measures designed to catch pre-cancerous tissue or early-stage tumors when treatment is most effective.
Surprising trends in lung and prostate cancer
Lung cancer experienced a significant increase in the diabetic population between 2010 and 2022, rising to be 23 percent more frequent in men and 25 percent more frequent in women with type 2 diabetes. The shift was especially notable among women, who had experienced a 12 percent lower incidence of lung cancer compared to women without diabetes in the 1996 to 2009 period.
In contrast, certain tumors not associated with obesity exhibited an opposing trend. Prostate cancer, which is the most common tumor among men, showed a 19 percent lower incidence in men with type 2 diabetes. Researchers noted that this finding aligns with previous studies suggesting that reduced testosterone levels in some men with type 2 diabetes might play a role in lowering prostate cancer risk, though the precise biological mechanism remains unconfirmed.
The authors stressed that the observational study was designed to describe evolving trends rather than prove that type 2 diabetes directly causes cancer. Specific lifestyle variables such as body weight, smoking habits, alcohol consumption, and physical activity levels were not analyzed in detail in the dataset, although researchers acknowledged these factors could influence the observed outcomes.
Shifting priorities in long-term diabetes care
The main message of the research is that clinical management of diabetes must evolve as treatments for traditional complications improve. Medical care has made substantial strides in reducing classic diabetes complications, including cardiovascular events and kidney failure.
Laurberg noted that as these traditional health complications become better controlled, cancer must take on a far more prominent position in long-term diabetes management. Integrating cancer prevention and targeted screening into routine follow-up care for people living with type 2 diabetes has now become a clinical necessity.
