Colon Cancer Linked to Lineage

A team of researchers from the University of Utah’s Huntsman Cancer Institute, headed by Dr. Deborah W. Neklason, Ph.D., have tracked a genetic mutation linked to increased risk of colon cancer back to an English couple who arrived in America about the time of the Pilgrims. Neklason’s findings appear in Clinical Gastroenterology and Hepatology.

Mr. and Mrs. George Frye were born in England in the 1590’s, were married in 1615, and sailed to America with at least two of their four children sometime in the early 1630’s. One also brought a spontaneous gene mutation called APC which increases the risk of developing colon cancer.

This genetic mutation causes a condition called attenuated familial adenomatous polyposis (AFAP), which makes people more prone to developing the polyps that can cause colon cancer. Without proper treatment, those with the AFAP mutation have a greater than two in three risk of developing colon cancer by the age of 80, compared to about one in 24 among the general population.

That gene was passed down to their descendants and is now responsible for a large percentage of colon cancer cases affecting hundreds of Americans. Neklason’s team studied two large families, one in Utah and one in New York, whose members both carry the gene mutation. The team first focused on the Utah branch of the family 14 years ago because its members had an unusually high risk of colon cancer. The 7,000 descendants through nine generations of the Utah family accounted for 0.15% of colon cancer cases in the state from 1966 to 1995, when the gene was first identified.

Detailed church records of this Mormon family, over the years, gave the researchers a wealth of genealogical information. Even though most of the records in the study related to the Utah portion of the family, the New York branch was eventually identified as well.

Dr. Neklason suspects that there are also many other families and said, “We just know about these two branches of the family. The significance of it going so far back is there are probably many branches of the family out there that aren’t aware of the mutation. In fact, this founder mutation might be related to many colon cancer cases in the United States.”

According to Neklason, an aggressive education and clinical intervention program among the couple’s Utah descendants may have prevented seven colon cancers. She says, “Knowing one has the condition can be life-saving. With intervention to remove the polyps, the risk goes to near nothing.”

Neklason’s team suggests that “genetic testing should be considered” for people with a family history of 10 or more colon polyps. Neklason says, “This study highlights that you need to pay attention to your family history.” However, cancer experts recommend that, no matter where your family comes from, colorectal cancer screening should begin at age 50, or sooner for high-risk patients.

Madeline Ellis

Provided by ArmMed Media