How Colonoscopies Save Lives

Posted on April 7, 2011


Recently, I was speaking with my father and the topic of his next colonoscopy came up.   After I gave him due praise for scheduling his appointment, he asked if it’s really worth it to have one done as often as is recommended.  I’d like to share with you some of the things I told him.

Colon cancer is the second leading cancer killer in the United States, and is far and away the most common gastrointestinal cancer.  March was National Colorectal Cancer Awareness Month, and hopefully many of you were reminded about screenings.  If everyone over the age of 50 went for regular screenings, it has been estimated that between 60-90% of deaths from colon cancer could be prevented (that’s potentially 30,000-45,000 lives saved) .  There are two main ways that getting a colonoscopy may save your life:

  1. A precancerous colon polyp is detected, and removed, during a routine colonoscopy – you never develop colon cancer.
  2. You have developed colon cancer, but it was detected early at your routine colonoscopy – when treated early, colon cancer has excellent survival rates.

But how does colon cancer develop, and why does removing a polyp potentially save someone’s life?  The vast majority of colon cancers progress through several stages, acquiring various genetic mutations along the way – it is believed that the process of transformation from normal tissue to full-blown adenocarcinoma occurs over approximately 10 years.  Below is a graphical representation of this progression:

Progression of colorectal cancer

(As an aside, the COX-2 overexpression above is likely to be implicated in the preventive benefit of aspirin, which is not currently recommended, but can be considered an added incentive for those already taking low-dose aspirin for cardiovascular health.)

Not all polyps are destined for cancer in all individuals, but if you clip off a polyp, you may have prevented a cancer – it’s that simple.  So continue to go for your regular screenings.

If you wait until signs and symptoms develop, you may have forfeited valuable time an altered the course of your care.  People with colon cancer may notice no symptoms whatsoever, or may experience abdominal pain & constipation, blood in the stools, or unexplained weight loss.  Additionally, uncharacteristically thin stools may be a sign of an obstruction.

It’s important to speak with your doctor about getting screened if you’re over 50, but also if you’ve had a close family member who’s had colon cancer before the age of 50, as this may mean your screenings should start earlier.

Take a look at this great educational video put out by The Visual MD (some of the statistics in the opening vignette are different from those reported here).

Posted in: Health, Medicine