New Study Confirms Colonoscopy Reduces Colon Cancer Deaths from Both Left Sided Lesions AND Right Sided Lesions
It has been widely noted that colonoscopy is a test that can help prevent colon cancer. Colonoscopy is an endoscopic procedure where a physician uses a long, slender telescopic tube to visually examine the entire lining of the colon and through which biopsies can be done if needed. 1,2,3
Colonoscopy reduces the incidence of colorectal cancer by early detection, as well as allowing for a physician to remove pre-cancerous polyps, which typically may take up to 10 years from initial appearance to develop into a cancer. Polyps, which are small growths in the lining of the colon, occur in about 25% of men and 15% of women over the age of 50. Currently, in the United States, colonoscopy is recommended beginning at age 50 for persons at average risk and earlier if patients are at higher risk due to family history or other diseases of the colon (previous polyp, previous colon cancer, ulcerative colitis, Crohn’s Disease). 1,2,3,4
In 2008 there were approximately 150,000 cases of colorectal cancer diagnosed and nearly 50,000 deaths. Almost three-quarters of these cancers arise in the colon with the remainder occurring in the rectum. 5
A physician performs colonoscopy. In most cases the physician is a gastroenterologist (also called a GI specialist). The procedure is performed in an outpatient center or hospital under light to moderate sedation. Patients can almost always go home the same day. Perhaps the most annoying aspect of the procedure is the prep required the day before, which involves using one of a variety of laxative type products to cleanse the colon so that an adequate visualization may be made. 1,2,3,4,5
To date we have known that colonoscopy clearly offered advantages in terms of early detection of lesions and polyps which were in the rectum and left side of the colon. These areas of course are the most easily reached during endoscopic examination. There has been less enthusiasm about the ability of the procedure to offer similar advantages when lesions and polyps occur on the right side of the colon. The right side of the colon of course is more difficult to reach and in some patients, depending upon their individual anatomy, it may not be possible to reach the most distant part of the right colon, called the cecum. The cecum is where the small intestine connects with the colon and is also the location of the appendix. 4,5
A recent study published in the Annals of Internal Medicine (Vol. 154, no 1, 22-30, Jan 3, 2011) indicates that colonoscopy does indeed improve the likelihood of identifying and removing early lesions of the right side of the colon. The study, performed in Germany, indicated that colonoscopy reduced the risk of colorectal cancer by 77%. The risk reduction was greatest, as expected on the left side, 84%, but was also significant on the right side at 56%. The improvement in outcomes was seen in both sexes and for all stages of colorectal cancer. Patients under the age of 60 had the lowest level of benefit, which most likely reflects the lower incidence of cancers the younger the patient population. 6
This study has generated great attention and has been widely reported on in other venues. 7,8,9,10
One aspect of the study that has led to speculation is why there are differences in rates of detection using colonoscopy. Clearly, the most significant factor is the experience base of the physician performing the procedure. Gastroenterologist are physicians who have completed a residency in internal medicine followed by specialty training in gastro-intestinal disease, diagnosis, treatment as well as endoscopic procedures such as colonoscopy. Currently, in many cases, colonoscopy is performed by primary care physicians and in some cases surgeons For the most part, these physicians have lower levels of training in the procedure and perform them less frequently. Having said that, it is clear that the rate of detection of polyps varies not only between groups of physicians, but also among gastroenterologists. 11
So what does this all mean? First, screening for colorectal cancer works and colonoscopy is an essential part of that screening as we age. As note, for most of us that is after the age of 50, usually once every 10 years, or 5 years if polyps have been detected. Second, it matters who does the procedure, with the most important aspects being training and experience. Some advocate that patients should specifically ask their doctor what their personal detection rate is for polyps and how often they are able to examine the entire colon.
In summary then, early detection remains the key element in prevention of cancer related deaths. When the organ system in question is the colon, colonoscopy is clearly one of the key elements in that early detection.
* Colonoscopy Even More Beneficial Than Thought - New Study Confirms Colonoscopy Reduces Colon Cancer Deaths from Left Sided and Right Sided Lesions http://is.gd/HE40Eg