According to the results of a European case-control study published by Molina-Montes et al in the journal Gut, one of the most recently identified types of diabetes—type 3c, or pancreatogenic diabetes—could also be an early manifestation of pancreatic cancer.
Pancreatic cancer has a high mortality rate—around 95%—since it is usually diagnosed at an advanced stage because of the absence of symptoms in its early stages. Therefore, the report would imply that it may be possible to make an earlier diagnosis of pancreatic cancer, since its findings allow classifying patients with diabetes type 3c as a population with an increased probability of having early-stage pancreatic cancer.
Diabetes and Pancreatic Cancer
It is estimated that around 50% of patients with pancreatic cancer also present with diabetes. However, it is a challenge for researchers to figure out which is the cause and which is the consequence. Until now, the most common approach has been to study if diabetes could cause pancreatic cancer.
“Our team turned the equation around and, for the first time, we asked the question whether pancreatic cancer could cause diabetes,” explained Núria Malats, MD, PhD, senior author of the paper and Head of the Genetic and Molecular Epidemiology Group at the Spanish National Cancer Research Centre (CNIO), in a statement. “Using innovative epidemiologic and statistical analysis strategies, we found that pancreatic cancer is the cause of the development of [type 3c] diabetes in 26% of cases.”
Type 3c Diabetes
Type 3c, or pancreatogenic, diabetes is characterized by an inflammation of the pancreas that interrupts insulin production. It is estimated to represent around 5% to 10% of all diabetes cases in Western countries, but currently, there are few specific markers for this type—it is often misdiagnosed as type 2 diabetes. More precise markers to identify it correctly are required not only to provide adequate treatment to patients, but also because a correct classification may assist in an early diagnosis of pancreatic cancer.
Study Methods and Results
To conduct the study, the team used data from more than 3,500 patients enrolled in PanGenEU, a large European study involving centers from six countries, to analyze the relationship between multiple risk factors and pancreatic cancer.
“Using the information from our study, national health systems could identify [patients with possible]—yet undetected—pancreatic cancer, if the patients, in addition to having type 3c diabetes, also have certain risk factors associated with this cancer, such as being obese or a smoker,” said Dr. Malats. “All of these factors would help family doctors better select patients who could benefit from more active monitoring or entering screening programs.”
The researchers wanted to test if type 2 diabetes could also be connected to this cancer, but in this case, the study was unable to establish a clear causal link. “We have seen that the relationship between pancreatic cancer and type 2 diabetes is very complex, with obesity playing a role, too. Further studies are required to fully understand how the metabolic state is reached in which all these phenomena arise.”
Disclosure: The study was funded by the Spanish Health Research Fund, the Carlos III Health Institute, CIBERONC, the Spanish Thematic Network for Cooperative Research in Cancer, the European Cooperation in Science and Technology, the Italian Association for Cancer Research, Cancer Focus Northern Ireland, and ALF (Sweden). For full disclosures of the study authors, visit gut.bmj.com.
