Colorectal cancer (CRC) is one of the few cancers that can be prevented with screening. In the United States, it is recommended that everyone over the age of 50 be screened for CRC. If you have a family history of colon polyps, cancer at an early age or certain chronic medical conditions you may be encouraged to be screened starting at an earlier age.
Although the incidence of CRC and cancer-related deaths is decreasing, colon cancer screening remains underutilized. Consequently, CRC remains the third most common cancer worldwide and the second leading cause of cancer deaths.
One of the main barriers to CRC screening is the lack of awareness of the disease. CRC tends to not be discussed as openly as other conditions such as breast or lung cancer. Furthermore, the thought of undergoing a colonoscopy is not appealing to anyone. This is compounded by the fact that there is a general misperception about the study.
Colonoscopy can detect early tumors, and more importantly pre-cancerous growths of tissue called polyps. Polyps can be removed at the time of the procedure, thereby preventing you from ever developing cancer.
Know what to expect at a colonoscopy
Preparation for a colonoscopy involves using a prescription laxative the day before the procedure to clear the colon. Prior to the study, anesthetic medications providing “twilight” sedation are given through an IV. You are able to follow commands under twilight sedation, but remain comfortable if not asleep during the entire exam.Once sedated, a long thin flexible tube with a light and a high-definition (HD) camera at the tip is inserted through the rectum and advanced to the end of your colon. The total length of the exam is typically 20 to 30 minutes.
I tell almost all of my patients that the hardest part of the exam is the preparation the day before the procedure. Many patients wake up from the sedation unaware that the test has already been performed. At Penn the preparation has been improved so the standard laxative solution is no longer a gallon of fluid, but is a more palatable combination of Miralax® dissolved in Gatorade®.
Alternatives to standard colonoscopy
Frequently, I am asked if there are alternatives to colonoscopy for CRC screening. Several newer promising technologies are currently under development for CRC screening.CT colonography or “virtual colonoscopy” is a technique whereby a series of X-rays are used to create 2- and 3-dimensional images of the colon and rectum to evaluate for large polyps and tumors. Virtual colonoscopy has the advantage of being a less invasive test that does not require sedation. However, this procedure does expose you to ionizing radiation. While one CT is unlikely to be harmful, recurrent exposure to ionizing radiation may pose a health risk to certain individuals.
Unfortunately, CT colonography can only reliably detect polyps greater than 5mm in size or early cancers. Colon polyps smaller than 5mm may be missed. Furthermore, if a polyp or tumor is detected, a colonoscopy is required for removal of the polyp or to biopsy the area of interest for a tissue diagnosis. Finally, in order for this test to be effective, you still have to drink the colon preparation solution before the examination.
Other new technologies under development are fecal immunochemical test (FIT) and colon capsule endoscopy.
FIT involves submitting a stool sample to analyze for the presence of occult blood. The sample can be collected in the comfort of your own home without the need for a bowel preparation; however, since this test only detects the presence of blood in the stool, it only identifies tumors or advanced polyps that are bleeding. FIT does not accurately identify early precancerous polyps.
Colon capsule endoscopy is an intriguing new method in which you swallow a capsule containing small cameras that take pictures of your digestive tract. Since this technology relies on cameras, you still have to do the colon preparation (the hardest part of the colonoscopy exam) and if a polyp or lesion is identified a subsequent colonoscopy is required for biopsy or removal of the polyp.
The bottom line is that roughly 80 percent of CRCs can be prevented with adequate screening and colonoscopy screening saves lives. I encourage everyone to begin the dialogue about CRC screening with their physicians. While no screening test is 100 percent perfect, colonoscopy remains the best method of screening for most individuals.
Are you 50 years old or older? Make an appointment at Penn Medicine for your routine colonoscopy by calling 1-800-789-PENN (7366).
March is Colorectal Cancer Awareness month – learn more.
