Mayo researchers look to chromosome for clues on colon cancer

A chromosome abnormality could provide a warning sign for the development of colon cancer in people under 50, Mayo clinic researchers report.

In a study looking at blood samples from 114 colon cancer patients under the age of 50 and blood samples from 98 people with no history of cancer, Mayo researchers found that young people who developedcolon cancer had abnormally short telomeres – the caps on the ends of chromosomes – adding to previous studies that linked the shortening of telomeres with colon cancer cells.

The study results were presented Saturday at the annual meeting of the American Society of Human Genetics in San Diego.

Based on their findings, researchers believe that colon cancer in people under 50 is biologically different than forms of the disease in people over 50.

People who develop colon cancer about 15 years earlier than most patients are more likely to have telomere shortening, Mayo researchers found, while men with colon cancer were more likely to have telomere shortening than women with the disease.

Colon cancer in younger patients is often more advanced than in older patients at the time of diagnosis, the report suggested.

"Young-onset colorectal cancer is more likely to present at a later stage and to be more poorly differentiated," reads the report. "Young patients are also more likely to develop rectal cancer compared with the older-onset population."

"Finding this association between colon cancer patients and increased telomere shortening is exciting because, if validated, it really opens up new possibilities for new treatment strategies," Lisa Boardman, lead researcher and a specialist in gastrointestinal malignancies at the Mayo Clinic, said in a release.

"For example, we know that telomere length can be repaired, so we want to look at telomere maintenance genes which, when defective, might very well contribute to cancer," she said.

In 2007, an estimated 20,800 Canadianswill be diagnosed with colorectal cancer and 8,700 will die of it, according to the Canadian Cancer Society (CCS).

CCS predicts that on average,400 Canadians will be diagnosed with colorectal cancer and 167 Canadians will die of colorectal cancer every week.

Though young people have much lower rates of colon cancer, each year in the U.S. 25,000 people aged 50 and under develop the disease, according to the report.