Shifts in the trend: cancer mortality among diabetics on the rise

Type 2 diabetes is associated with a few secondary diseases, of which cardiovascular events are common. A study shows a growing danger for diabetics.

Study investigates cancer-specific mortality in type 2 diabetes

• This was a retrospective cohort study.
• It included 138,000 people aged 35 years and older who were first diagnosed with type 2 diabetes between the years 1998 and 2018.
• All cases were categorised into subgroups by gender, ethnicity, socioeconomic status, BMI and smoking status.
• The data came from the representative UK GP database Clinical Practice Research Datalink (CPRD). They were linked to clinic databases and socioeconomic and demographic data.

Development of all-cause mortality in diabetics

First, the researchers led by Dr Suping Ling from the Leicester Diabetes Research Centre looked at the development of all-cause mortality in diabetics. Over the follow-up period, 28.5% of people with diabetes had died.

On closer inspection, the researchers made an interesting observation: while overall mortality decreased across all age groups, cancer-specific mortality increased in diabetics, at least in older diabetics aged 75 and over. It was 8.2% at the end of the survey. This means that almost one third of all deaths were due to cancer. Pancreatic, liver, colon and endometrial cancers accounted for a large proportion.

Special risk groups are affected

Women, socially disadvantaged people, smokers and obese people with a BMI of 35 kg/m2 and above were particularly affected by the rising cancer mortality. For women, it increased by 1.5% annually, compared to only 0.5% for men. Among the socially disadvantaged, the increase also averaged 1.5% per year. However, smokers (+ 3.4%) and very obese people (+ 5.8%) in particular succumbed to their cancer more frequently.

Cancer as the leading cause of death in diabetes

It so happens that cancer as a cause of death among diabetics has steadily increased in recent years compared to other fatal diseases, especially among the elderly. While just over 20 years ago, 20% of 75 to 84 year-olds died of cancer, the proportion was around 35% in 2010 and has remained stable since then. Among the very old aged 85 and over, the proportion of cancer deaths has risen even more significantly from around 10% in 1998 to just under 40% in 2018.

Cancer mortality in diabetics compared to the general population

Finally, the researchers compared the mortality of diabetics with that in the general population. Overall, it was increased by 8%, whereas cancer-specific mortality in diabetics rose by 18%. Diabetics with colorectal, pancreatic or liver tumours were particularly at risk. Their risk of dying from cancer was more than double that of the general population.

Specific prevention measures and early diagnosis needed

The data presented from the last 20 years are alarming. The increasing cancer mortality in people with type 2 diabetes, contrary to the general trend, and the high risk for certain subgroups such as older people, women and the socially disadvantaged, require specific cancer prevention measures and increased research in this area. The goal must be to diagnose cancer earlier in diabetics. To this end, tumour diseases must be considered in the management of diabetics just as much as cardiovascular complications.