Type 2 diabetic men need bowel cancer screening

With the culmination of the 18-year-long 'Fremantle Diabetes Study', a startling new link has been revealed between type 2 diabetes and colorectal cancer in men.

Results from the huge data set have uncovered while both men and women with type 2 diabetes are at greater risk for all cancers, men with the condition are doubly at risk of developing cancer of the bowel.

UWA biostatistician and research fellow Assistant Professor Wendy Davis says the observational study was a huge investment in gathering data.

The average follow up was 11 years (because patients can pass away during the time they are being observed), and patients were first recruited in 1993.

"We have valid data up until June last year," A/Prof Davis says.

In order to conduct the study, researchers including UWA Winthrop Professor Tim Davis who presented the findings at the Australian Diabetes Society annual meeting in Perth last month, identified as many people as possible with the condition in a postcode defined area around Fremantle Hospital.

"At the start of the study there were about 120,000 people living in that area and of those we identified 2,258 with type 2 diabetes. We were able to recruit 1,426," A/Prof Davis says.

"We were able to show the cohort was representative of the community in terms of age, sex and ethnicity.

"When people were recruited they underwent a three-hour assessment including a physical exam, screenings for diabetes complications – such as eye or heart disease – and were asked many questions about lifestyle behaviours and mental health.

"We then follow them clinically with a check up every year and we also had the opportunity to link the data with the Western Australian data linkage system.

"So we could determine when people were hospitalised, died, or were put on the cancer registry."

A/Prof Davis says while the data cannot suggest why men with diabetes are at a two-fold higher risk of developing colorectal cancer, she says other studies do offer insights such as poor diets, lifestyle factors and increased smoking.

Regardless, in light of the results, the researchers have called for a lower bowel screening age to be set for men suffering from type 2 diabetes.

For the general public, the screening age is set at 50 but A/Prof Davis says for at-risk men the age could be as low as 40.

Now, the Fremantle Diabetes Study has recruited another round of participants and is set to launch again as the cases of diabetes continues to rise in Perth.

By Laura Glitsos

(Source: ScienceNetwork WA)

More information

For more information on bowel cancer, types of bowel cancer, and its tests, treatments and useful videos, see Bowel Cancer (Colorectal Cancer).

For more information on diabetes, including different types of diabetes, blood glucose and dietary control, and long-term complications, as well as some useful videos, see Diabetes.