Genetic Study Could Prevent Colon Cancer

AFAP (attenuated familial adenomatous polyposis) is a condition caused by a genetic mutation which causes the growth of colorectal polyps that have the potential to become cancerous. Since the risk of developing colon cancer is higher for two out of three people living with the AFAP mutation (one in 24 for the general population), tracing back the defective gene in the family medical history could prove extremely benefic for preventive treatments and early diagnosis of this disease.
A group of researchers led by Deb Neklason, Ph.D at the University of Utah traced the genetic condition to a Utah pioneer family and their 7,000 descendents. They also linked a New York family with the same genetic condition to the group, tracing back the genealogy of two families over 16 generations to Mr. and Mrs. George Fry, who likely arrived in Massachusetts colony aboard the William & Mary in the 1630s. The research involved studying the Utah Population Database (UPDB) archive.

The findings made possible the identification of individuals at the risk and living relatives of the Frys were able to avoid colon cancer, as doctor Neklason explains: “Our work demonstrates that colon cancer can be prevented with proper screening and care. Aggressive education and clinical intervention over a seven-year window in the Utah family has already prevented seven colon cancers”.

Researchers studied an estimate of 200 cases of the Frys descendants carrying the genetic mutation and were able to identify a gene called NAT1 which could be responsible for polyp growth and also found relations between dietary habits and general colon cancer risk, suggesting that aspirin, calcium, caffeine, fish-fats, bananas might have some protective effects whilst a high fat diet and obesity increases the risks. The team is currently working on a chemoprevention study which could make polyps shrink or recede entirely and finding more people with the AFAP mutation and helping them prevent colon cancer.

Neklason suggests that thousands more people could be at risk: “It could have an impact on a lot of people out there. We ran some numbers and if this mutation accounted for just 0.1 percent of all of the colon cancers in the U.S. that would equal 150 cases a year and cost about $7.5 million per year to treat.”

With more than 150,000 cases diagnosed in the US alone each year, colon cancer is the third most common cancer in this country. Whilst most cases don’t derive from known inherited mutations, for AFAP carriers an early diagnosis could prove to be their salvation.

Image: A Utah family from 1900, one of the many that appear in the Utah Population Database. This particular family did not carry the colon cancer gene. (Credit: Geri Mineau, University of Utah)