Colorectal Cancer Screening and Prevention

Colon cancer is the third most common cause of cancer death in the United States, causing an estimated 57,000 deaths each year. It often strikes without any warning signs or symptoms. The majority of colon cancers begin as a polyp, an abnormal growth of tissue found on the wall of the colon. When polyps are detected, they may be removed at the pre-malignant state and prevent the development of colon cancer.

Who is at risk for colon cancer?

All adults are at risk and risk generally increases as we get older.

Average Risk:

• Every adult over age 50.

High Risk:

• <Family history (parent,sibling,child) of colon cancer or an adenomatous polyp.
• Familial polyposis Coli Syndrome
• Personal history of colon polyps
• Personal history of Ulcerative Colitis or Crohn’s Disease.

How is Colon Cancer Diagnosed?

If people experience symptoms like those of colorectal cancer,they need to make an appointment with their family physician, a gastroenterologist, a physician specially trained in the management of digestive disorders, or a colon and rectal surgeon, a specialist in treatment of diseases of the colon. What are the symptoms of colon cancer? Colon cancer is a silent stalker, usually causing no symptoms until the disease is very advanced. If you experience any of the following signs or symptoms see your doctor.

• Rectal bleeding or pain
• Change in a regular bowl habit
• Unexplained anemia
• Weight loss
• Lower abdominal pains

What are the Symptoms of Colon Cancer?

Colon cancer is a silent stalker, usually causing no symptoms until the disease is very advanced. If you experience any of the following signs or symptoms see your doctor.

• Rectal bleeding or pain
• Change in a regular bowl habit
• Unexplained anemia
• Weight loss
• Lower abdominal pains

How to prevent Colon Cancer

Like breast,cervical,and prostate cancer screening, everyone should be SCREENED to prevent colon cancer.

• At age 50 if no family history
• Ten years prior if family member was diagnosed

Preliminary evidences suggest the following can be helpful.

• Increased vegetables and fiber in the diet
• Calcium and Folic Acid
• 1 aspirin a day
• Reduction of animal fat in the diet

Screening Tests That Are Recommended

For normal risk individuals,screening tests begin at age 50 and the preferred approach is a screening colonoscopy every 10 years; an alternate strategy consists of a annual stool test for blood and a flexible sigmoidoscopic exam every 3 to 5 years.

• Fecal Occult Blood Test — The fecal occult blood test is also known as FOBT. The main use for the FOBT is as a screen for early cancer. It is a lab test used to check stool samples for hidden (occult) blood. Occult blood in the stool may indicate colon cancer or polyps in the colon or rectum, though not all cancers or polyps bleed. Typically occult blood is passed in such small amounts that it can be detected only through the chemicals used in a fecal occult blood test.
• Sigmoidoscopy — A Sigmoidoscopy is a specialized screening test for colorectal cancer.. People age 50 and older who have no symptoms may have a sigmoidoscopy to check for suspicious areas inside the colon. Those who have symptoms, such as abdominal discomfort, persistent diarrhea, or blood in the stools, have this test to help determine the exact cause of these problems.
• Barium Enema — The Barium enema is a special x-ray of the large intestine, which includes the colon and rectum. The test may be done in an office or a hospital radiology department. It is done after the colon is completely empty.
• Colonoscopy — A colonoscopy is a screening and diagnostic procedure during which the inside walls of the entire colon are examined. The doctor uses an instrument called a colonoscope. This is a flexible fiber optic tube that bends around with the shape and turns of the colon. The colonoscope is typically attached to a video camera and monitor. This allows the doctor to clearly view the inside walls and lining of the colon.
• Virtual Colonoscopy — Virtual colonoscopy combines MRI or CT scans with sophisticated computer software to produce three dimensional images of the colon and rectum. The test is less invasive than conventional colonoscopy. A computer combines all the images to form the thee- dimensional pictures of the colon and then they are viewed on a video monitor. Virtual Colonoscopy may be performed to:
  
  • Diagnose colorectal cancer
  • Examine those with a family history of colon cancer
  • Follow up after an incomplete or failed colonoscopy
  • Follow up after a previous finding of colon cancer or polyps
  • Look for polyps

A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions.

The Elderly and Virtual Colonoscopy

THURSDAY, Jan. 28 (HealthDay News) — Virtual colonoscopy is a safe and effective way to screen older patients for colorectal cancer, a new study indicates.

Researchers looked at the use of computed tomographic colonography (CTC) in 577 patients aged 65 to 79 and found it an effective way to screen for colorectal cancer in elderly patients. It produces low referral – for-colonoscopy rates that are similar to other screening tests covered by Medicare, and doesn’t result in unreasonable levels of additional testing because of extracolonic findings, they noted.

“There have been questions raised that factors such as the [colonoscopy] referral rate and extracolonic work-up rates would be too high in an older population for CTC to be a cost-effective, frontline colorectal cancer screening exam. Our results suggest otherwise and that these rates remain in a reasonable range,” principal investigator Dr. David H. Kim, an associate professor of radiology at the University of Wisconsin School of Medicine and Public Health, said in a news release.

Among the findings:

• Advanced neoplasia (abnormal growth) was detected in 7.6% (44 of 577) of patients. There was no statistically significant difference between the older patients and the general screening population in terms of the characteristics of advanced neoplasia. This indicates the accuracy is similar to that shown in studies involving younger patients.
• The overall referral rate to optical colonoscopy was 15.3% (88 of 577), which is slightly lower than other Medicare-covered colorectal cancer screening exams such as flexible sigmoidoscopy.
• Potentially significant extracolonic findings were seen in 15.4% (89 of 577) of patients, with a work-up rate of 7.8% (45) of patients. Most of the extracolonic diagnoses were vascular aneurysms.
• No major complications, such as colon perforations, occurred.

“The lack of complications, particularly no perforations, attests to the safety of this procedure even in the older population. Given what we know of the increasing risk for complications for optical colonoscopy in older patients, perhaps we should consider CT colonography more strongly in this particular group,” said Kim.

The study is published in the February issue of Radiology. — Robert Preidt

SOURCE: American College of Radiology/American Roentgen Ray Society, news release, Jan. 26, 2010

U.S. News and World Report 

in the January 2010 issue reported that 45% of colon cancers, 36% of breast cancers and 69% of esophageal cancers would never occur if Americans ate better, weighed less, and exercised more, estimates the American Institute for Cancer Research. “it’s not just cancers of the digestive tract. What you eat and what you weigh affect certain other cancer types as well”, says Alice Bender, AICR’s nutrition communications manager. The organization recommends limiting red meat to 18 (cooked) ounces per week and loading up on plant based foods, which are high in the phytochemicals and antioxidants known to inhibit cancer cell growth in lab animals. Those with the deepest colors–like purple grapes, blueberries, and leafy green vegetables — tend to have the most beneficial compounds. One recent study, for example, showed that eating foods such as broccoli and kale that have lots of sulforaphane, an antioxidant, suppresses a bacterium linked to stomach cancer.