Increased colorectal cancer risk for extended family members, younger endometrial cancer patients

Women under age 50 who have been diagnosed with endometrial cancer, and first, second and third degree relatives of patients with colorectal cancer may have an increased risk of developing colorectal cancer (CRC), according to two separate studies unveiled today at the American College of Gastroenterology's (ACG) 77th Annual Scientific meeting in Las Vegas. Two other CRC-related studies presented at ACG 2012 investigated the impact of gender, race and obesity on the incidence of adenoma and advanced adenoma detection rates—suggesting that overweight African American and Hispanic men may be at greater risk for precancerous polyps which if not detected early enough could lead to colorectal cancer.

Highlights of Colorectal Cancer Research from the ACG Annual Scientific Meeting

*"Risk of Colorectal Cancer after Diagnosis of Endometrial Cancers: A Population-Based Study"
Women diagnosed with endometrial cancer under age 50 had a "marked increased risk" of being diagnosed with colorectal cancer in a historical cohort study by researchers at the University of Manitoba who linked several large longitudinal databases routinely collected in Manitoba, including the Manitoba Cancer Registry and some of Manitoba Health databases. The researchers followed 3,115 women diagnosed with endometrial cancer between 1987 and 2008 and 15,084 age-matched controls up to December 2009.

Women younger than 50 in the cohort at the time of diagnosis of endometrial cancer had an approximately four -fold increased risk of being subsequently diagnosed with colorectal cancer as compared to the age matched women in the general population. The risk was even higher (seven fold higher) for colorectal cancers occurring in the upper part of the colon (right colon). There was no increased risk for colorectal cancer among women diagnosed with endometrial cancer, when they were 50 years old or older.

Endometrial cancer is a cancer that starts in the inner lining of the womb (uterus) called the endometrium. In the U.S., endometrial cancer is the most common cancer found in women's reproductive organs. The chance of a woman having this cancer during her lifetime is about one in 38, according to the American Cancer Society.

"This study suggests there is an increased risk of colorectal cancer after a diagnosis of endometrial cancer among young women," said co-investigator Dr. Harminder Singh. He said, therefore these patients need close follow-up particularly for colorectal cancers occurring in the upper part (right-side) of the colon. "Colorectal cancer screening should start at a younger age in such women."

*"Elevated Risk of Colorectal Cancer in Relatives of Patients with Colorectal Cancer: A Population-Based Study in Utah"

In the first population-based assessment of the risk of colorectal cancer in extended family members of patients with CRC, researchers from the Huntsman Cancer Institute in Salt Lake City, UT reported that first, second and third degree relatives of individuals with colorectal cancer had an increased risk of developing CRC themselves—with the strength of the association based on the degree of kinship, according to lead investigator, Niloy Jewel Samadder, M.D.