Pancreatic cancer associated with rapidly deteriorating diabetes
Results from a study presented at the European Cancer Congress 2017 (ECCO 2017) in Amsterdam, the Netherlands showed that rapid deterioration of type 2 diabetes after diagnosis may be an early sign of pancreatic cancer.
Between 2008 and 2013, the investigators identified 368,654 patients with type 2 diabetes from Belgium and 190,371 patients with type 2 diabetes from Lombardy, Italy. The number of patients diagnosed with pancreatic cancer in these two cohorts was 885 and 1,872, respectively. Results showed that the risk for pancreatic cancer was significantly increased among patients receiving incretin therapy vs those receiving nonincretin antidiabetic drugs (NIAD) (Belgian cohort adjusted hazard ratio [HR], 2.12; Lombardy cohort adjusted HR, 2.17; overall adjusted HR, 2.14). [ECCO 2017, abstract 540]
The investigators also found that the risk of developing pancreatic cancer decreased overtime after initiation of incretin therapy. In the Belgian cohort, the HR decreased from 3.3 at 3 months to 2.3 at 3–6 months, 2.1 in 6–12 months, and 1.7 at 1 year after the first prescription of incretin therapy. In the Lombardy cohort, the HR was 1.4 for the first 6 months and 1.2 for the next 6 months.
Furthermore, the switch from NIAD to incretin therapies was more rapid in patients diagnosed with pancreatic cancer vs those without pancreatic cancer (median, 372 days vs 594 days; p<0001).
Incretins (principally glucagonlike peptide-1 [GLP-1] analogues and agonists) are drugs that decrease blood glucose by stimulating the pancreas to produce insulin. These drugs are prescribed when oral antidiabetic medications can no longer control blood glucose levels. [Cell Metab 2013;17:819-837]
“It was postulated that incretin therapies could promote the occurrence of pancreatic cancer. Our study showed that incretin therapies are often prescribed to patients whose diabetes is caused by undiagnosed pancreatic cancer that becomes symptomatic. This creates a picture where incretin drugs seemingly cause pancreatic cancer. In reality, however, pancreatic cancer is the cause of deterioration of diabetes, which leads to the prescription of incretins. This phenomenon is called ‘reverse causation’,” explained Ms Alice Koechlin from the International Prevention Research Institute in Lyon, France.
“Doctors and their patients should be aware that the onset of diabetes or rapidly deteriorating diabetes could be the first sign of hidden pancreatic cancer… We hope that our results will encourage the search for blood markers indicating the presence of pancreatic cancer, which would guide decisions to perform a confirmation test, such as endoscopy,” commented Koechlin.Pancreatic cancer causes more than 331,000 deaths per year, ranking it as the seventh leading cause of cancer death. In 2012, about 338,000 individuals had pancreatic cancer worldwide. It is one of the deadliest cancers with an overall 5-year survival rate of about 6 percent. [World J Gastroenterol 2016;22:9694–9705]