Researchers have found that people with type 2 diabetes (T2D) develop cancer at more than twice the rate of those without the condition, with the disparity growing significantly in recent years, according to a nationwide Danish study presented at the European Association for the Study of Diabetes annual meeting in Milan.
Study Overview and Data Analysis
The research team, led by Tinne Laurberg, MD, of Steno Diabetes Center Aarhus, analyzed registry data from all Danish adults spanning 1996 to 2022. They tracked 75,540 first cancer cases in individuals with T2D and 635,323 among those without diabetes, using sex-stratified, age-standardized incidence rates to assess differences over time.
Before adjusting for age, cancer incidence stood at 16.6 cases per 1,000 person-years in people with T2D compared to 7.7 in those without. Age-standardized analyses revealed a persistent gap that has widened: cancer incidence was 12% higher in men and 22% higher in women with T2D during 2010-2022, up from 9% and 15% respectively in the earlier period (1996-2009).
Data curves show cancer rates among people without diabetes have declined in recent years, while remaining raised among those with T2D. Obesity-related cancers explain much of this difference, representing 38% of cases in men with T2D versus 29% in men without, and 66% versus 58% in women.
Specific Cancer Patterns
Pancreatic cancer showed the most pronounced relative excess, with incidence 2.65 times higher in men and 2.58 times higher in women with T2D during 2010-2022. Colorectal cancer rates were 17% higher in men and 14% higher in women with T2D. Lung cancer incidence shifted dramatically, becoming 23% higher in men and 25% higher in women in the later period after being similar or lower in the earlier one.
Prostate cancer incidence was 19% lower among men with T2D in the more recent timeframe. These patterns extend earlier research focused on cancer mortality rather than incidence. A 2024 Danish study found cancer had become the leading cause of death among people with T2D as cardiovascular deaths declined.
Similar findings from an English study in The Lancet Diabetes & Endocrinology documented cancer’s growing contribution to mortality in diabetes populations. The researchers note their analysis does not prove T2D causes cancer or quantify factors like obesity, smoking, or physical activity. Instead, they identify immediate clinical action: boosting participation by people with T2D in existing cancer screening programs for common cancers such as colorectal and breast cancer.
