The African-American population has the highest risk of developing and dying from colorectal cancer and yet they are the least likely ethnic group to undergo a life-saving colonoscopy screening. This is the finding from a new study led by researchers at Vanderbilt University Medical Center.

Harvey Murff, MD, MPH, assistant professor, and lead author for the study says family history is a powerful predictor of who will develop colorectal cancer but even when a first-degree relative is diagnosed, African-Americans are less likely to get a recommendation for the screening from their healthcare providers than whites and other minorities.

During a colonoscopy, a tube is threaded through the colon and small intestine. The tube can detect and remove polyps, which are masses that can become cancerous if allowed to remain intact. Polyp removal is widely thought to be the very best method available for the prevention of colon cancer.

African-Americans with a first-degree relative diagnosed with colorectal cancer are at a two to three times higher risk of developing the disease themselves. They are also likely to develop the disease 10 years earlier than someone who does not have a family history of the disease. Nevertheless, they are only about half as likely to get a physician’s recommendation for a colonoscopy than a white patient with the same family history.

Patients of all ethnicities say the reason they don’t get colonoscopies, even when colon cancer runs in the family, is that they don’t get the recommendation to do so from their healthcare provider.

The research team used data representing 41,830 patients who are involved with the Southern Community Cohort Study, an ongoing investigation of cancer and mortality differences in 12 southern states. The study identifies participants by race and by rural and urban populations.

According to the National Cancer Institute, 148,810 Americans will develop colon or rectal cancer during the year 2008. They expect 49,960 deaths. Lifestyle choices, such as a high-fat diet rich in meats and cigarette smoking, are also risk factors for colorectal cancers.

In most cases, routine colonoscopy screenings should begin at age 50 but for anyone with a family history of colorectal cancers, screening at age 40 is preferred.

The March 24 issue of the Archives of Internal Medicine carries complete study details.