Type 2 diabetes - or its rapid deterioration - can be an early warning sign for pancreatic cancer
30 January 2017Patients and their doctors should be aware that the onset of diabetes, or a rapid deterioration in existing diabetes that requires more aggressive treatment, could be a sign of early, hidden pancreatic cancer, according to new research presented at the European Cancer Congress this week.
Professor Philippe Autier from the International Prevention Research Institute in Lyon, France, analysed information from prescription databases for nearly 850,000 patients with type 2 diabetes in Lombardy (Italy) and Belgium between 2008-2013.
They found that during this period, of the 368,377 type 2 diabetes patients in Belgium, 885 went on to be diagnosed with pancreatic cancer. Similarly, of the 456,311 patients in Lombardy, 1,872 went on to receive a pancreatic cancer diagnosis.
Using the prescription data, the research team showed that half of all the patients were diagnosed with pancreatic cancer within one year of being diagnosed with type 2 diabetes and being given their first prescription to control it.
“In Belgium 25% of cases were diagnosed within 90 days and in Lombardy it was 18%. After the first year, the proportion of diagnosed pancreatic cancers dropped dramatically,” said Professor Autier.
Among patients who already had type 2 diabetes and were managing it with oral anti-diabetic drugs, the switch to treatment with incretins or insulin happened faster among patients who were subsequently diagnosed with pancreatic cancer. In addition, patients whose condition deteriorated an who were switched to injections of insulin were found to have a seven-fold increased risk of being diagnosed with pancreatic cancer.
Prof Autier said: “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. Incretin therapies… are typically prescribed when the oral anti-diabetic drugs can no longer control blood glucose levels. Because of their stimulating effects on the pancreas, it has long been thought that the incretin therapies could promote the occurrence of pancreatic cancer.
"However, it is known that pancreatic cancer can cause diabetes. Our study shows that incretin therapies are often prescribed to patients whose diabetes is caused by a still undiagnosed pancreatic cancer. Because the pancreatic cancer finally becomes symptomatic and is thus diagnosed, it looks like it is the intake of incretin drugs that could be the trigger of the pancreatic cancer, while in reality, it is the pancreatic cancer that causes a deterioration of diabetes, which is followed by the prescription of incretins. This phenomenon is called ‘reverse causation’. Our study also shows that the reverse causation observed for incretin drugs is also observed for other anti-diabetic therapies, in particular for insulin therapy.
“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.”
Maggie Blanks, Chief Executive of Pancreatic Cancer Research Fund (PCRF) 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.
“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.”