Pancreatic Cancer and Diabetes Link

Although it is just the 10th most prevalent of all cancers, pancreatic cancer is the 4th leading cause of cancer mortality. Just 6% of affected individuals live 5 years after diagnosis.

Almost half of newly diagnosed pancreatic cancer present as new-onset diabetes mellitus and 50% to 80% of people with pancreatic cancer are diabetic. People with long-standing adult-onset diabetes appear to be roughly twice as likely to develop pancreatic cancer. Weight gain, hyperinsulinemia, and accelerated IGF-1 and -2 signaling seem to contribute to tumor formation.

The American Society of Clinical Oncology (ASCO) had several sessions on pancreatic cancer at its 50th Annual Meeting in May and a multinational team has summarized the new information in an article in the July issue of Journal of the Pancreas.

One of the findings came from German researchers, who presented a retrospective cohort study that followed 78,599 patients with diabetes and 392,995 patients without diabetes for a maximum of 12 years. They found diabetic individuals were more likely to develop lung, esophageal, pancreatic, kidney, colorectal, and endometrial cancer. Diabetics were 2.17 times more likely to develop pancreatic cancer.

At ASCO’s 2014 Gastrointestinal Cancers Symposium, 2 important facts emerged:

• In the distant future, we may be able to screen for pancreatic cancer. A small prospective cohort study identified biomarkers that could detect pancreatic adenocarcinoma among diabetic patients that was highly accurate.
• Metformin can add 4 to 6 months to the median overall survival of a population with pancreatic adenocarcinoma. In comparison, targeted therapies, like bevacizumab in lung cancer, add only 2 months to the overall survival of non-small cell lung cancer.

These findings are addressed in a previous issue of Journal of the Pancreas.

Epidemiological evidence substantiates that diabetes increases cancer risk, but temporal or a causal relationship between the two pathologies eludes us.