COLORECTAL CANCER SCREENING & PREVENTION TECHNIQUES

Colorectal cancer is the third most common form of cancer in the country, affecting up to 5% of the population over the course of a lifetime. Those with a family history of the disease or who have had breast, uterine, or ovarian cancer are at a higher risk, as are those who have a history of extensive inflammatory bowel disease, such as ulcerative or Crohn's colitis.

One of the more difficult aspects of colorectal cancer detection is that, in many cases, the cancers or polyps do not initially cause any symptoms. The goal is to recognize the potential for disease as early as possible, in order to facilitate prevention or cure. That’s why screening is so significant; it identifies whether an asymptomatic person has a disease or condition that might lead to cancer.

Surveillance, on the other hand, involves testing those with a history of colorectal cancer, or who have been identified as being at a higher risk for developing it.

Many people with colorectal cancer do not experience any symptoms (including rectal bleeding and stomach pain) until the cancer is quite advanced – which is why it’s often referred to as a “silent” disease. The possibility for a cure is unfortunately much lower after symptoms develop, which is why testing is important.

Most cancers begin as polyps (non-cancerous growths). Removing the polyps may result in preventing the cancer and avoiding the need for major surgery.

There are various screening tests that can be performed. One of the more common tests is called fecal occult blood testing, which involves testing the stool to detect any blood that might not be visible to the naked eye. Since it only detects cancers and polyps that are bleeding at the time of the test, however, fecal occult blood testing is typically used in conjunction with other screening techniques.

Flexible sigmoidoscopy is performed in the office, and allows your doctor to look directly at the lining of the colon and rectum. The test focuses on the lining of the lower one-third of the colon and rectum, where many polyps and cancers typically reside. Combined with fecal occult blood testing, flexible sigmoidoscopy can detect many cancers and polyps.

If a flexible sigmoidoscopy results in the detection of a polyp or cancer, or if a patient is considered at a higher risk for developing colorectal cancer, then the doctor will likely perform a colonoscopy. This procedure allows for a full visual examination of the colorectal lining, in order to diagnose problems and to perform biopsies and to remove polyps. Colonoscopies are typically performed on an outpatient basis, and involve very little discomfort.

Barium enema, or x-ray of the colon, is another procedure used to detect large polyps or tumors. It is less accurate for smaller tumors, and not quite as effective as a colonoscopy.

For people without any identified risks, a digital rectal examination and testing of the stool for hidden blood are recommended every year beginning at age 40. A colonoscopy should be performed at age 50, or earlier for those with a history of colorectal cancer in their family. American Cancer Society guidelines can be found at www.cancer.org.

• People who have had any pre-cancerous polyps found and removed in the past. A colonoscopy is advised one to three years after the first examination.
• Those with a close relative (sibling, parent, or child) who has had colorectal cancer or a pre-cancerous polyp. Screening should begin at age 40, or five years before the age at which the youngest relative was diagnosed.
• People with a family history of colorectal cancer, including close relatives and across several generations. These people should receive genetic counseling and consider testing for a condition called hereditary nonpolyposis colorectal cancer. Colonoscopy is recommended every two years starting between ages 20 and 30, and every year after age 40.
• People with a family history of an inherited disease called familial adenomatous polyposis (FAP). Counseling and genetic testing are recommended, to determine if they are carriers for the gene that causes the disease. If the gene is detected, a flexible sigmoidoscopy should be performed every year beginning at puberty; if polyposis is present, a total colectomy, which involves removing all the colon and rectum, may be recommended.
• People with a personal history of colorectal cancer. A complete examination (consisting of either a colonoscopy or flexible sigmoidoscopy with a double-contrast barium enema) is recommended within a year after the cancer is initially detected and surgically removed. If exam results are normal, a follow-up exam should be performed within three years.
• People with a history of extensive inflammatory bowel disease for at least eight years. A colonoscopy is recommended every one to two years.
• Women with a personal history of breast, ovary, or uterine cancer. These people have a 15% lifetime risk of developing colon cancer, and should undergo a colonoscopy screening every five years, beginning at age 40.