Danish researchers at the Steno Diabetes Center have found that women with type 2 diabetes face a 22 per cent higher risk of developing cancer than those without the condition.
Men with type 2 diabetes face a 12 per cent greater overall cancer risk compared to men without the metabolic disease, according to data gathered by scientists in Denmark.
The findings, presented at the Annual Meeting of the European Association for the Study of Diabetes, highlight a growing link between obesity, type 2 diabetes and deadly tumours across Europe.
The European Association for the Study of Diabetes is a major medical organization dedicated to advancing research and patient care across the continent. The Steno Diabetes Center, located near Copenhagen in Denmark, is a specialized research hospital focused on diabetes treatment and prevention.
The increased danger was most pronounced for obesity-related cancers, including kidney, pancreatic and liver tumours. Men with type 2 diabetes were 45 per cent more likely to develop these specific cancers, while women faced a 30 per cent higher risk.
Bowel cancer was around 17 per cent more common among diabetes sufferers overall. Lung cancer rates were up to 25 per cent higher among those with the condition.
Specific tumour risks by gender
The pattern of cancer risk varied significantly between men and women across different organ sites. Women with type 2 diabetes faced an 8 per cent increased risk of breast cancer, which remains the most common cancer affecting women worldwide.
Bowel cancer was 17 per cent more likely in men with type 2 diabetes. Conversely, men with type 2 diabetes were found to have a 19 per cent lower risk of prostate cancer than men without the condition.
Lung cancer rates were around 25 per cent higher in women with type 2 diabetes between 2010 and 2022. This represents a striking reversal from the period between 1996 and 2009, when women with the condition were 12 per cent less likely to develop lung cancer.
To reach these conclusions, researchers analyzed nationwide health records covering virtually the entire adult population of Denmark between 1996 and 2022. Over the 27-year study period, the team identified 75,540 cancers among participants with diabetes and 635,323 cancers among those without the condition.
Denmark maintains centralized public health registries that track medical diagnoses and treatment histories across its population. This comprehensive record system allows medical researchers to monitor long-term health trends across millions of citizens over several decades.
Expert warnings and prevention priorities
Dr Tinne Laurberg, a consultant pathologist at Steno Diabetes Center and co-author of the study, said the findings demonstrate the urgent need for "prioritising cancer prevention" among type 2 diabetics.
Dr Laurberg emphasized that preventive efforts are critical for widespread forms of the disease. "This is especially important for common obesity-related cancers, such as colorectal and post-menopausal breast cancer," she said.
The study authors are urging healthcare providers to recognize cancer as a major long-term threat for diabetic patients. "Cardiovascular and kidney disease prevention remains a key priority in diabetes care," Dr Laurberg said. "However, as outcomes for these complications improve, cancer may require greater attention."
Pathology is the branch of medical science concerned with the study of disease causes and effects, particularly through the laboratory examination of body tissue samples for diagnostic or forensic purposes.
Biological causes and study limitations
The researchers stressed that their findings show an association between type 2 diabetes and cancer risk, rather than proving that diabetes directly causes tumour growth.
The Danish study was unable to account for several major cancer risk factors, including body weight, smoking status, alcohol consumption and physical activity levels. Researchers noted that these unmeasured variables may partly explain the observed differences in cancer rates.
Scientists believe excess body fat may help drive cancer by increasing levels of hormones and growth signals in the body. Elevated levels of insulin can encourage abnormal cells to grow and divide rapidly.
Insulin is a vital hormone produced by the pancreas that allows cells to absorb glucose from the bloodstream for energy. Type 2 diabetes occurs when the body fails to respond properly to insulin or cannot produce enough of it, leading to persistently high blood sugar levels.
While the exact mechanism connecting diabetes to cancer remains unclear, experts suspect high levels of insulin, blood sugar and chronic inflammation all play a role. Hormonal differences between sexes may also explain why risk patterns differ, as sex hormones influence how sensitive the body is to insulin.
Rising diagnosis rates in younger adults
The research arrives amidst broader concerns about rising cancer rates among younger adults. Diagnoses in people aged between 25 and 50 have increased by a quarter over the past two decades, representing the fastest rise of any age group.
Some experts link the surge in early-onset cancer to expanding waistlines, as obesity rates doubled over the same 20-year period. Diagnoses of type 2 diabetes have simultaneously jumped almost 70 per cent among young women in England over the last decade.
A full explanation for why cancer levels are increasing in young people remains elusive. However, experts at The Institute of Cancer Research and Imperial College London believe the only data aligning with the rise is the steady increase in overweight and obesity levels since the 1990s.
The Institute of Cancer Research and Imperial College London are leading academic institutions in the United Kingdom dedicated to scientific research, medical education and oncology breakthroughs.
Researchers are continuing to investigate other potential contributing factors behind the rise in cancer among young people. These include consumption of ultra-processed foods, exposure to "forever chemicals", changes in the gut microbiome and widespread historical antibiotic use.
Impact on British healthcare and prevention
Previous data shows that cancer is now the leading cause of death among people living with type 2 diabetes in Britain. More than five million people in the United Kingdom are estimated to be living with the condition.
Excess weight plays a dominant role in the diabetes epidemic, with nine in ten cases of type 2 diabetes linked to being overweight. Currently, two-thirds of British adults are either overweight or obese, while almost one in four children aged 10 to 11 fall into the obese category.
Being overweight is the second-biggest preventable cause of cancer after smoking. The World Health Organisation links obesity to at least 13 different types of cancer, including breast and bowel malignancies.
The World Health Organisation is the specialized international public health agency of the United Nations, tasked with setting global health standards and monitoring disease trends worldwide.
Health experts emphasize that around four in ten cases of type 2 diabetes could be prevented through lifestyle modifications. Maintaining a healthy weight, exercising regularly and eating a balanced diet remain the most effective ways to lower the risks of both type 2 diabetes and cancer.
