Excluding skin cancer, colorectal cancer is the third most commonly diagnosed cancer in females in the United Stated and second most common in Utah. Cancer of the colon and rectum are very closely related and have many features in common. For this reason, researchers simply refer to them collectively as colorectal cancer. Death from colorectal cancer has decreased over the past decade. This reduction is largely attributed to increased screening procedures called colonoscopies that detect colorectal cancer at an early stage. It is quite common for doctors to find polyps, which are benign or non-cancerous tumors. These polyps, if left in the colon, can develop into colon cancer. Screening colonoscopies allow physicians to remove these polyps before they become malignant or cancerous .
If colorectal cancer is detected before it has spread to other areas of the body, 5-year survival rates are greater than 90%. However, less than 40% of colorectal cancers are discovered at this early stage. Once the cancer has spread to the other areas of the body, (metastatic colorectal cancer), 5-year survival rates are less than 10% .
Some risk factors for colorectal cancer cannot be changed. These risk factors include being over the age of 50, family history of colorectal cancer, having a history of colorectal polyps, chronic inflammatory bowel disease such as Crohn’s disease and ulcerative colitis, and genetic mutations. (Inflammatory bowel disease is quite different from the more common irritable bowel syndrome which does not increase risk of colorectal cancer). Other risk factors for colorectal cancer can be changed by altering behavior and improving lifestyle patterns. These risk factors include obesity, high fat and high animal-source diets, physical inactivity, smoking, and heavy alcohol use .
Researchers have been studying genetic mutations in colorectal cancer. They have recently identified nearly 200 mutated genes that are linked to cancer by tumor initiation, tumor growth, cancer spread, and cancer control . Only about 20% to 30% of people with colorectal cancer have a family history of the disease and only 5% to 10% of those with a family history have an inherited genetic susceptibility [1,3].
Researchers at the University of Utah recently discovered a molecule that is associated with some colorectal cancers. By genetically disabling this molecule called adenomatous polyposis coli (APC) in zebrafish, researchers were able to protect them from the effects of genetic mutation .
Many times colorectal cancer has very ambiguous symptoms or no symptoms at all. For this reason, it is recommended that all people over the age of 50 see a physician for a complete physical exam, including a digital rectal exam, stool testing for occult bleeding, and colonoscopy or flexible sigmoidoscopy. Screening colonoscopies are usually recommended every 3-5 years. People at higher risk for developing colorectal cancer such as genetic mutations, family history, or other colorectal conditions may need to be screened at an earlier age than the general population [1,3].
Insurance coverage seems to play a sizable role in whether people get screened for colorectal cancer. Due to the cost of screening colonoscopies, those who do not have health insurance coverage do not usually get screened. In Utah residents aged 50 years and older, those with health insurance are twice as likely to get screening colonoscopies as those without health insurance .
Demographics also seem to play a role in whether Utah residents get screening colonoscopies. Those individuals living in non-urban areas (considered either rural or frontier) average 2% to 15% less likelihood for screening colonoscopies in the past five years than their urban counterparts .
Racial/ethnic disparities exist in both incidence and mortality rates of colon cancer victims. Black women have higher incidence and mortality rates of colorectal cancer than any other racial/ethnic group of females in the United States while Hispanic women have the lowest incidence and mortality rates. However, in Utah, Hispanic women have the second highest rate of colorectal cancer, following black women. See figures 2 and 3 for details .
- American Cancer Society. Available Online at http://www.cancer.org. Retrieved on Dec 24, 2006.
- Johns Hopkins Kimmel Cancer Center. Available Online at http://www.hopkinskimmelcancercenter.org. Retrieved on Jan 7, 2007.
- MedicineNet, Inc. owned and operated by WebMD. Available Online at http://medicinenet.com. Retrieved on Jan 7, 2007.
- University of Utah Huntsman Cancer Institute, News Center. Available Online at http://unews.utah.edu. Retrieved on Jan 7, 2007.
- Utah Cancer Registry. Available Online at http://uuhsc.utah.edu/ucr/statistics&pubs.html.
- Surveillance, Epidemiology and End Results (SEER) by the National Cancer Institute. Retrieved Jan 7, 2007 http://seer.cancer.gov/fstats
- Utah’s Indicator-Based Information System for Public Health: Available Online at http://ibis.health.utah.gov. Retrieved on Oct 11, 2006.