The Medical Minute: Family tree one factor in colorectal cancer risk

Mar 16, 2011 By Maria J. Baker

March is National Colorectal Cancer Awareness Month. In 2010, according to the American Cancer Society, there were more than 142,000 new cases of colorectal cancer in the United States and over 51,000 people died from the disease. Overall, the lifetime risk for developing colorectal cancer is approximately one in 20, or 5 percent, of men and women in the general population.

The good news is that is preventable. Routine screening, beginning at 50 years of age for the general population, can identify abnormal growths in the colon and rectum, and by removing these so-called polyps, can prevent colorectal . Screening can also detect colorectal cancer, if it has already developed, at an earlier, more curable stage. Unfortunately, the bad news is that an estimated 41.8 million average-risk individuals aged 50 or older have not been screened for colorectal cancer.

Certain individuals in the general population have a much higher risk to develop colorectal cancer. Factors that increase a person’s risk to develop colorectal cancer include getting older, a prior history of colorectal polyps, inflammatory bowel disease, such as Crohn’s or ulcerative colitis, and lifestyle habits, such as a high-fat, low-fiber diet with an excess of red and processed meats, obesity, smoking, heavy alcohol use, and a lack of regular physical activity. In some individuals, their family history may represent the most significant risk factor.

Approximately 75 percent of patients with colorectal cancer have sporadic disease with the remaining 25 percent having a positive family history, suggesting a shared genetic or environmental etiology. Fortunately, only five to six percent of colorectal cancer overall is felt to be hereditary, such that a mistake or mutation in a single gene puts certain family members at much higher risk to develop colorectal cancer, and potentially other cancers as well.

, previously referred to as hereditary non-polyposis colorectal cancer or HNPCC, represents the most common hereditary cause of colorectal cancer. Approximately 1 in 400 to 1 in 500 individuals in the general population are estimated to have Lynch syndrome. Knowledge, as they say, in this condition, is power. Not only should individuals with Lynch syndrome start their colonoscopies earlier (at 20-25 years of age) and have them more frequently (every 1-2 years), they should also be screened for stomach and small intestine cancer, urinary tract cancers involving the kidneys and ureters, and the hepatobiliary tract, including the gallbladder, bile duct, pancreas and liver. Further, women with Lynch syndrome should be aware of the increased risk for both endometrial and ovarian cancer and offered the option of prophylactic surgery following childbearing.

Red flags in a person’s personal or family history that may indicate an increased risk for Lynch syndrome include colorectal or endometrial cancer under 50 years of age, two or more Lynch-associated cancers in the same person, or multiple relatives with Lynch-associated cancers. Likewise, an excessive number of precancerous colorectal can be a red flag for not only Lynch syndrome, but also a less common hereditary condition called familial adenomatous polyposis (FAP). If you or your family members have any of these red flags, you may want to consider the option of genetic counseling and testing.

Explore further: Survival differences seen for advanced-stage laryngeal cancer

add to favorites email to friend print save as pdf

Related Stories

Wide genetic testing for Lynch Syndrome cost effective

Nov 19, 2010

Widespread genetic testing for Lynch Syndrome appears to be a cost-effective strategy for identifying those at risk for colorectal and endometrial cancer, according to a report in Cancer Prevention Research, a journal of the ...

Family history and screening for colorectal cancer

Jun 09, 2008

A new study indicates that African Americans with a family history of colorectal cancer are less likely to be screened than African Americans at average risk for the disease. There is also some evidence to indicate that AA ...

Recommended for you

Survival differences seen for advanced-stage laryngeal cancer

16 hours ago

The five-year survival rate for advanced-stage laryngeal cancer was higher than national levels in a small study at a single academic center performing a high rate of surgical therapy, including a total laryngectomy (removal ...

Gene test aids cancer profile

Nov 27, 2014

The first round of chemotherapy did little to suppress Ron Bose's leukemia. The second round, with 10 times the dose, knocked the proliferating blast cells down, but only by half.

Hospital volume not linked to costs of cancer surgery

Nov 26, 2014

(HealthDay)—Hospital surgical volume does not appear to correlate with Medicare payments for cancer surgery, according to research published online Nov. 24 in the Journal of Clinical Oncology.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.