Save Yourself from Colorectal
By Brent Lemberg, MD
Did you know that 40,000 to 50,000
people in the United States will die of colon cancer this year? It is the
second most common cause of cancer death in this country, with 150,000 new
cases diagnosed annually. The good news is that in the past 10 years the
incidence of colorectal cancer has begun to decline. The reason is that about a
decade ago, gastroenterologists started to perform many more screening
colonoscopies as health insurance companies began to cover the cost.
How have screening colonoscopies
affected the drop in colon cancer?
Colon cancer always starts with a
polyp, which is a small mass of tissue that develops on the inside wall of the
colon. In the earliest stage these polyps are typically not cancerous, cause no
symptoms, and can be removed easily during a routine screening colonoscopy.
However, if not removed, in 10 to 15 years these polyps can grow into cancer.
With the increasing national awareness of the role of screening colonoscopies
in early detection and removal of polyps, more people are getting screened
regularly and fewer people are developing colon cancer.
Who is most at risk for colorectal
Colon cancer does not discriminate.
It affects both genders and all ethnic groups, though the risk for colon cancer
is higher among African-Americans. Your risks also increase if you are over the
age of 50: the average age of newly diagnosed colorectal cancer patients is 60
to 65 years of age. Having said that, no matter what age you are you should see
your doctor if you have rectal bleeding because this cancer does occur in
people as young as 30.
Is a colonoscopy the only way to
screen for polyps in the colon?
The best screening test is the
standard optical colonoscopy. During this examination, a small tube with a tiny
light source is inserted into the rectum. It is slowly advanced through the
entire length of the colon, allowing the gastroenterologist to thoroughly
examine the walls of the large intestine. While there are other screening
modalities, they are not as good.
In the past few years, there has
been a lot of buzz about virtual colonoscopy, which uses CT scanning to
visualize the colon. A study published
in the New England Journal of Medicine in
September 2008, examined the efficacy of virtual colonoscopy as compared to
standard colonoscopy. The researchers found that virtual colonoscopy missed 10
percent of polyps bigger than one centimeter. A polyp this size has a high risk
of being cancerous and is one we would definitely remove during a standard
colonoscopy. The study also found that virtual colonoscopy missed up to 22
percent of polyps between 6 and 10 millimeters.
Shortly after this study was
published, the US Preventative Services Task Force came out with a position
paper stating they did not recommend virtual colonoscopy. The paper went on to
say that optical colonoscopy, which is performed with an endoscope, is the
preferred method of examination. In addition to missing a higher percentage of
polyps in the first place, should a polyp be discovered through virtual
colonoscopy, the patient would then have to undergo a standard optical
colonoscopy to have the polyp removed.
If you are 50 years old, please
talk to your doctor about scheduling a screening colonoscopy. If you have a
family history of colon cancer or if you are African-American, you should
schedule your first colonoscopy at age 40. Having regular colonoscopies every
ten years reduces your risk of colon cancer by 90 percent.
Lemberg is a board-certified gastroenterologist on staff at Cayuga Medical
Center and in practice with Gastroenterology Associates of Ithaca. He can be
reached at (607) 272-5011.