A presentation to the European Cancer Congress in Amsterdam reports that 50% of people in two sample groups who had been diagnosed with pancreatic cancer had been diagnosed with type 2 diabetes in the previous year and been given their first medication to control it.
Fewer than 5 out of 100 people can expect to be alive 5 years after being diagnosed with pancreatic cancer. Survival rates are poor because the cancer doesn't usually cause any symptoms until late in the disease.
The American Cancer Society estimates more than 53,000 people will be diagnosed with pancreatic cancer in 2017.
"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," Alice Koechlin, from the International Prevention Research Institute in Lyon, France, told the conference.
Insulin and the Pancreas
The study involved 368,377 people with type 2 diabetes in Belgium and 456,311 in Italy.
Among these patients over a 5-year period, there were 885 and 1,872 cases of pancreatic cancer diagnosed respectively.
The researchers found that patients had a 3.5 times higher risk of being diagnosed with pancreatic cancer compared to those on other non-insulin, non-incretin diabetes treatments in the first 3 months after their first prescription for a class of diabetes medications known as incretins. The risks decreased with time. These are hormones that stimulate the pancreas to produce more insulin.
Among patients who already had type 2 diabetes, the need to switch to injecting insulin because their condition got worse was associated with a seven-times-higher risk of being diagnosed with pancreatic cancer.
"Doctors and their diabetic patients should be aware that the onset of diabetes or rapidly deteriorating diabetes could be the first sign of hidden pancreatic cancer, and steps should be taken to investigate it," Koechlin said.
"The association between pancreatic cancer and type 2 diabetes has been an area of interest to researchers for several years, so it’s great to see studies generating new and potentially very valuable information which could alert clinicians to the need for further investigation in certain patients,” said Maggie Blanks, chief executive of the Pancreatic Cancer Research Fund, in a statement.
"We now need the work developing early diagnostic tests to catch up so that we can make use of this information as soon as possible. There are global efforts investigating biomarkers for pancreatic cancer in blood or saliva that may have diagnostic potential and the early research that PCRF has funded which identified biomarkers in urine is progressing towards a clinical trial.
"We may well be on the cusp of a significant improvement in both identifying those at higher risk and being able to diagnose quickly, so that appropriate treatment can start as soon as possible."
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.