Diabetes may be a warning sign for pancreatic cancer, suggests study

A new study analysed data on nearly a million patients with type 2 diabetes

The onset of diabetes, or a rapid deterioration in existing diabetes that requires more aggressive treatment, could be an early and hidden sign of pancreatic cancer, warns a new study that analysed data on nearly a million patients with type 2 diabetes.

Researchers found that 50 per cent of all pancreatic cancer cases in Lombardy, Italy and Belgium were diagnosed within one year of patients being diagnosed with type 2 diabetes and being given their first prescription to control it.

"In Belgium 25 per cent of cases were diagnosed within 90 days and in Lombardy it was 18 per cent. After the first year, the proportion of diagnosed pancreatic cancers dropped dramatically," said Alice Koechlin from the International Prevention Research Institute in France.

The researchers found that compared with patients who were able to continue with oral anti-diabetic drugs, patients in Belgium and in Lombardy had a 3.5-fold greater risk of being diagnosed with pancreatic cancer in the first three months after their first prescription for incretins (metabolic hormones that stimulate the pancreas to produce more insulin to lower blood glucose levels)

This fell to a 2.3-fold risk in the next three to six months, to a two-fold risk for the next six to 12 months and 1.7-fold risk after the first year.

Among patients who already had type 2 diabetes and were managing it with oral anti-diabetic drugs, the switch to incretins or insulin happened faster among diabetic patients who were subsequently diagnosed with pancreatic cancer.

In addition, a deterioration in their condition that necessitated them being switched to more aggressive anti-diabetic therapy with injections of insulin was associated with a seven-fold increased risk of being diagnosed with pancreatic cancer.

Koechlin and colleagues in Belgium and Italy used prescription data to identify 368,377 patients with type 2 diabetes in Belgium between 2008 and 2013 and 456,311 patients in Lombardy between 2008 and 2012.

The data were linked to pancreatic cancer cases in the Belgian Cancer Registry and the hospital discharge databases in Lombardy.

There were 885 and 1,872 cases of pancreatic cancer diagnosed during this time in Belgium and Lombardy respectively.

"Although it has been known for some time that there is an association between type 2 diabetes and pancreatic cancer, the relationship between the two conditions is complex," said Koechlin.

Pancreatic cancer is one of the most lethal cancers, partly because it is difficult to detect at an early stage and because there are few effective treatments for it.

Less than one per cent of people live for ten or more years after a diagnosis. Worldwide there were an estimated 338,000 cases of pancreatic cancer diagnosed in 2012 and 330,000 people died from it.