Colorectal Cancer
Colorectal cancer (CRC) accounted for approximately 1 million new cancer cases (9.4% of all newly diagnosed cancers) and 529,000 deaths worldwide in 2002.364 The incidence of CRC varies among populations, with the highest rates found in North America, Australia, New Zealand, and western Europe. The lowest incidence is found in Africa, Asia, and South America.364 In the United States, CRC is the third most common cancer. It is estimated that in 2008, approximately 108,070 people will be diagnosed with colon cancer and 40,740 with rectal cancer.8008 An estimated 50,640 people in the U.S. will die from CRC in 2008, accounting for almost 10% of all cancer deaths.8008 Between 1998 and 2004, the incidence rate of CRC declined 2.3% per year. In addition, mortality rates have declined over the past 20 years; the overall 5- and 10-year survival rates are 64% and 57%, respectively.8008 However, despite advances in screening, diagnosis, and treatment, survival rates for metastatic disease remain low; 10-year survival rates for individuals with metastatic CRC is approximately 10%.8008
Risk Factors
Risk factors associated with colorectal cancer (CRC) include but are not limited to, age, a personal or family history of CRC and/or polyps, and personal history of inflammatory bowel disease (IBD).8008 Physical inactivity, obesity, smoking, an excessive alcohol intake, high dietary intake of fat or red or processed meat, and low intake of fruits and vegetables also increase the risk for developing CRC.8008
Hereditary colon cancer syndromes have been identified, including familial adenomatous polyposis and hereditary nonpolyposis colon cancer (HNPCC).359 Familial adenomatous polyposis accounts for 1% of new cases of colon cancer, whereas HNPCC accounts for 5%–10%.384 In contrast, hormone replacement therapy and polyp removal are considered protective factors and decrease an individual’s risk of CRC.8022
Screening
According to the American Cancer Society, males and females who are at average risk for CRC should be screened starting at age 50 by fecal occult blood test (FOBT) or fecal immunochemical test (FIT) and sigmoidoscopy (repeated every 5 years with FOBT or FIT done annually) or by FOBT or FIT (annually), flexible sigmoidoscopy (every 5 years), a colonoscopy (repeated every 10 years, if normal), or double-contrast barium enema (repeated every 5 years, if normal). This schedule may be modified in moderate- or high-risk patients.359
Treatment Options and Survival Rates
Surgery is the most common treatment for CRC, and it can be curative if the cancer has not metastasized. Chemotherapy, with or without radiation, is recommended before or after surgery for CRC with lymph node involvement or if cancer has deeply penetrated the bowel wall. Certain biologic therapies are also options for patients with metastatic CRC. The 5-year survival rate for CRC that is detected and treated early is 90%; however, only 39% of CRCs are detected in early stages due to under-use of screening procedures and nonspecific, vague early symptoms. When looking at all stages combined, the 5-year survival rate is 64%. The survival rate continues to decline beyond 5 years.359
Content on this page was last reviewed on January 31, 2010.
Content on this page was last changed on January 12, 2010.
References:| 359. | American Cancer Society. Cancer facts & figures 2007. American Cancer Society website. http://www.cancer.org/downloads/STT/CAFF2007PWSecured.pdf. Accessed February 5, 2007. |
| 364. | Parkin DM, Bray F, Ferlay J, Pisani P. Global cancer statistics, 2002. CA Cancer J Clin. 2005;55(2):74-108. |
| 384. | Levin B. Colorectal cancer. In: Dale DC, Federman DD, eds. ACP Medicine Online. Based on: Dale DC, Federman DD, eds. ACP Medicine. New York, NY: WebMD, Inc.; 2006. http://acpmedicine.com . Accessed June 29, 2007. |
| 8008. | American Cancer Society. Cancer facts and figures 2008. American Cancer Society website. http://www.cancer.org/downloads/STT/2008CAFFfinalsecured.pdf . Accessed April 2, 2008. |
| 8022. | National Cancer Institute. Colorectal Cancer Prevention PDQ ® . National Cancer Institute website. http://www.cancer.gov/cancertopics/pdq/prevention/colorectal/HealthProfessional/page2 . Accessed April 8, 2008. |