Type 1 diabetes linked to pancreatic cancer risk

By Michele Rizzo

NEW YORK (Reuters Health) - It is well known that people with type 2 diabetes are at increased risk of pancreatic cancer, and now it seems that the risk extends to those with type 1 diabetes, researchers report. However, they point out that the risk is still very small.

Type 2 diabetes is associated with being overweight and is caused when the body becomes less responsive to the action of insulin, leading to high blood sugar levels. Type 1 diabetes arises, often in childhood, when the insulin-producing cells in the pancreas are damaged, usually by an aberrant immune reaction.

To assess the risk of pancreatic cancer in people with type 1 and young-onset diabetes, Dr. Richard J. Stevens and colleagues from the University of Oxford, UK, reviewed findings from nine population-based studies.

The likelihood of developing pancreatic cancer was twice as high in subjects with type 1 or young-onset diabetes as in people without diabetes, the team reports in the British Journal of Cancer.

This increased risk is similar in magnitude to that seen with type 2 diabetes.

There are many theories about the link between diabetes and pancreatic cancer, Stevens said in an interview with Reuters Health and "our results help narrow these."

For example, he said, "they rule out a cancer-inducing role of the insulin-producing beta-cells in the pancreas, because in type 1 diabetes these cells have largely or entirely been destroyed."

Stevens stressed that "people with type 1 diabetes should not be overly concerned about pancreatic cancer." As he explained, "Pancreatic cancer is an extremely rare disease, and twice a tiny risk is still a tiny risk."

People with diabetes "should remain focused on the common complications of diabetes such as heart disease, eye disease and kidney disease, and the many measures -- including diet, exercise, and medication -- that can be taken to avoid them," Stevens concluded.

SOURCE: British Journal of Cancer, February 2007.