In the United States, colorectal cancer is the fourth most common cancer in men, after skin, prostate and lung cancers. It is also the fourth most common cancer in women, after skin, lung and breast cancers. No one knows the exact causes of colorectal cancer, also called colon cancer. Doctors seldom can explain why one person develops the disease and another does not.
Research has shown that people with certain risk factors are more likely than others to develop colorectal cancer. These include:
People who think they may be at risk should discuss this concern with their doctor. Physicians may be able to suggest ways to reduce the risk and can plan an appropriate schedule for checkups.
Colon cancer screening can detect polyps, early cancers and changes that can be treated before symptoms develop. Regular screenings may decrease deaths and prevent pain caused by colorectal cancer. Colon cancer screening is as effective as breast cancer screening when it comes to saving lives.
There are three ways to screen for colon cancer:
The American Cancer Society makes the following recommendations:
Beginning at age 50, both men and women should be screened for colon cancer. Some recommend that African Americans begin screening at age 45. People with certain digestive diseases (such as ulcerative colitis) or a family history of colon cancer may need earlier and more frequent testing. The Centers for Disease Control reports that incidence of colon cancer has decreased significantly by 2.3 percent per year from 1998 to 2004 for men and women combined, and that success can be attributed in part to screenings.
Screening options for patients with an average risk for colon cancer:
There is not enough evidence to determine which screening method is best. Colonoscopy is the most thorough method, but it takes longer, requires sedation, is slightly riskier and is much more expensive than a sigmoidoscopy.
Signs and Symptoms
While possible signs of colon cancer include a change in bowel habits or blood in the stool, other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur.
Treatment depends partly on the stage of the cancer. In general, treatments may include:
Stage 0 colon cancer may be treated by removing the cancer cells, often during a colonoscopy. For stages I, II and III cancer, more extensive surgery is needed to remove the part of the colon that is cancerous.
There is some debate as to whether patients with stage II colon cancer should receive chemotherapy after surgery. You should discuss this with your oncologist.
Almost all patients with stage III colon cancer should receive chemotherapy after surgery for approximately six to eight months. The chemotherapy drug 5-fluorouracil has been shown to increase the chance of a cure in certain patients.
Chemotherapy also is used to treat patients with stage IV colon cancer.
For patients with stage IV disease that has spread to the liver, various treatments can be directed specifically at the liver.