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.
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
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."