Colon Cancer – An Ounce of Prevention….

Breaking bad news is one of the hardest parts of my job.  There are times that I have to tell someone they have a new diagnosis – whether diabetes, a sexually transmitted disease or cancer – and it is not easy.  It is even more difficult when I know that some diagnoses can be PREVENTED!  So I am a huge advocate for preventing a disease whenever I can.  March is Colorectal Cancer Awareness month – and this week’s post is an update on how to prevent ever having to hear your doctor utter the horrible words – “You have colon cancer.”

Colon and Rectal cancer will be diagnosed in over 125,000 people in the US this year.  Over 50,000 people will die from it.  Colon cancer is the 3rd most common cancer in the United States.  And the majority of cases are preventable.  So how are colon and rectal cancer prevented?  By screening for them – doing tests that look for cancer – or ideally pre-cancerous lesions, and removing them.  How do we decide when and what tests to do?  By looking at your medical history and your family medical history and determining your risk.

For those at average risk, the current recommendations for colon cancer screening is to begin at age 50.  Why age 50?  At age 50, the likelihood of colon cancer or a colon polyp – a bump in the tissue of the colon that can turn into cancer – becomes high enough that the benefit of doing a test and removing the lesions outweighs the risk of the testing and the procedure.

So what increases your risk of colon or rectal cancer?

  • Colon cancer or precancerous polyps in a first degree relative (parent, sibling)
  • Prior colon polyps yourself
  • A  history of Ulcerative Colitis
  • A family history of a hereditary colon cancer syndrome – familial adenomatous polyposis (FAP) or hereditary non-polyposis colon cancer (HNPCC)

How do we screen for colon cancer?

  • Fecal Occult Blood Testing (FOBT)
  • Colonoscopy
  • Flexible Sigmoidoscopy
  • Barium Enema
  • CT Colonoscopy (also called a Virtual Colonoscopy)

 What are the advantages and disadvantages of each screening method?

  • FOBT  – done yearly; a small amount of stool is placed on a card, and a chemical added to see if there is any blood in the stool.  Best done with 3 consecutive bowel movements at home and returned to the doctor.  This helps detect cancer because polyps or cancer often bleed.  If blood is detected, a colonoscopy is required.
  • Colonoscopy – this a procedure,  done under anesthesia or sedation, where a flexible tube with a camera is inserted in the rectum and passed through the entire colon.  It directly visualizes the colon and any polyps can be removed (preventing them from becoming cancer).  It should be done at least every 10 years (if totally normal) and more frequently depending on risk and findings.  The 10 year interval is based on studies that show it takes about 10 years for a polyp to turn into cancer.  It requires a “prep” – emptying the colon of any stool the day prior to the procedure.  This is the “gold standard” for colon cancer prevention.
  • Flexible Sigmoidoscopy – this is a procedure, where a flexible tube similar to a colonoscopy tube is inserted in the rectum, and the first two feet of the colon are looked at for polyps or cancer.  If they are detected, they can be removed.  It requires a prep to clean the colon.  It can miss any polyps beyond the two feet of colon closest to the rectum.  If any polyps are found, either a colonoscopy or a barium enema to look at the rest of the colon are recommended.
  • Barium Enema – this is an X-ray test where barium is inserted into the rectum and outlines the inside of the colon.  An X-ray is taken to see the outline, allowing polyps that change the outline to be seen.  It requires a prep before the procedure to empty the colon.  If the study is abnormal, a colonoscopy is required.
  • CT Colonoscopy (Virtual Colonoscopy) – a study using a CT scan and computer reconstruction to see the inside of the colon, looking for polyps or cancer.  It takes less time than a traditional colonoscopy.  There is radiation exposure. It does require the same prep as a colonoscopy, and a small tube is inserted in the rectum to pump air into the colon to allow for better imaging.  If the study is abnormal, a colonoscopy is required.

How does this affect my practice?

I recommend a colonoscopy for all my patients over 50 years old.  If there is a family history of colon cancer I recommend starting 10 years before the relative’s age when they had colon cancer or age 50 – whichever is sooner.

Most people dread the prep – cleaning out their colon more than the procedure itself.  Most people sleep through the actual procedure.  The preps have gotten better in that you don’t need to drink as large a volume of liquid as in the past.  It could be considered the most useful cleanse ever!  

I also recommend FOBT yearly between colonoscopies, though current guidelines to not require this.  I make this recommendation because FOBT is easy, and people may delay their colonoscopy or a polyp may develop a little faster than the usual 10 years.

As far as flexible sigmoidoscopy and barium enema, I only recommend them if there is a reason a colonoscopy can not be done.  CT colonoscopy gives a great image of the colon, and if totally normal gives good reassurance that there is no colon cancer.  However, if there is an abnormality, a colonoscopy must be done, requiring a second prep and procedure.

Colon cancer is preventable – and if diagnosed early, curable.  The important thing is to talk to your doctor about your risk and get screened – any method of screening is better than nothing!  I recommend colonoscopy as it allows the best visualization of the colon – and removal of polyps at the same time – one stop shopping.  Telling someone we prevented them from getting cancer is much more fulfilling than telling them they have colon cancer!

The path to wellness begins with a proper diagnosis

Some useful links:

CDC colon cancer screening guidelines

American Cancer Society colon cancer detection guidelines

American Cancer Society colon cancer overview