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Double trouble
Are pancreatic cancer and type 2 diabetes related?


April 2015

Does pancreatic cancer lead to Type 2 diabetes or is it the other way around? Itís the medical version of the chicken or the egg. Researchers know that there is a correlation between the two diseases, but they are still not sure which one comes first. Studies show that people who have Type 2 diabetes have twice the risk of developing pancreatic cancer compared with people who donít have diabetes. The question remains, is Type 2 diabetes a risk factor for ó or a symptom of ó pancreatic cancer?

According to Dr. Ben George, medical oncologist at the Froedtert & the Medical College of Wisconsin, finding that answer is an active area of research. "There is a modest association between diabetes and pancreatic cancer, but it is unclear whether diabetes associated with pancreatic cancer is a cause or a consequence," he says.

What they do know is that that roughly 50 percent of pancreatic cancer patients develop diabetes, and the majority of these patients develop it in the two years preceeding the diagnosis of pancreatic cancer. "We also know that the risk of developing pancreatic cancer in newly diagnosed diabetic patients falls over time ó meaning individuals that carry a diagnosis of diabetes for 24 or fewer months have a higher risk of developing pancreatic cancer than those who carry the diagnosis of diabetes longer. This may suggest that diabetes is a consequence and not a cause of pancreatic cancer," says George.

The confusion occurs because pancreatic cancer can influence the way the body regulates insulin and blood sugar, which could result in diabetes. At the same time, Type 2 diabetes can damage the pancreas and lead to the development of pancreatic cancer. "Since diabetes and pancreatic cancer both share some risk factors, such as obesity, insulin resistance, etc., it is extremely difficult to tease out whether diabetes is a cause or consequence of pancreatic cancer," says George.

Considering that pancreatic cancer often doesnít exhibit symptoms until it is very advanced and incurable, should someone recently diagnosed withType 2 diabetes be screened for pancreatic cancer? George says no. "Currently, there is no evidence to support routine screening for pancreatic cancer in someone with a new diagnosis of Type 2 diabetes," he says. "This is partly because the incidence of Type 2 diabetes is very high and that of pancreatic cancer is very low. Therefore, it is difficult to justify routine screening of all patients who develop Type 2 diabetes."

Although he does not recommend screening for everyone, George says there are exceptions. "Individuals who carry a higher risk of developing pancreatic cancer, like those with two first degree relatives with pancreatic adenocarcinoma, any three family members with pancreatic adenocarcinoma and those who carry hereditary cancer risk syndromes, should talk with their physician about being screened if they do develop new onset diabetes."


This story ran in the April 2015 issue of: