The National Cancer Institute estimates colorectal cancer, occurring either in the colon or rectum, will kill nearly 50,000 people in 2015, making it the second leading cause of cancer deaths in the United States.
While the numbers are alarming, it’s important to know colorectal cancer is preventable and almost always treatable. People who are diagnosed with early stage colorectal cancer have a 92 percent survival rate, although up to 65 percent are not diagnosed until the disease is considered late stage.
Who needs to be screened?
Doctors recommend that most people get their first colonoscopy at age 50. The majority of colorectal cancer is diagnosed in patients in their 60s.
Colorectal cancer generally has no symptoms. It is not often tied to a genetic predisposition, and it is indiscriminate about whom it afflicts. The only effective way to protect against colorectal cancer is to get a colonoscopy. Although many of us don’t want to talk about it, the outpatient screening procedure is quick and painless. Often, the conversation about a colonoscopy is more uncomfortable than the procedure itself.
“I always remind my patients that getting a colonoscopy is just like getting a mammogram or a pap smear for women, or a prostate exam for men, or even just an ordinary skin check — these are all simple screening tests,” said Dr. Leslie Browder, M.D., of MountainView Hospital. “We all have to do them occasionally, and they can potentially lead to lifesaving treatment.”
*There are not many definitive patterns pointing to causes for colorectal cancer, which is why everyone should get a colonoscopy in their early 50s. It also may be recommended that some people get screened earlier — namely, people who have a family history of colorectal cancer, people who have certain inflammatory conditions such as ulcerative colitis or Crohn’s disease, and people who show late-stage cancer symptoms such as abdominal pain and bleeding, weight-loss or anemia.
What happens during a colonoscopy?
A colonoscope is inserted into the rectum and through the colon, which allows the doctor to see inside the person's bowels and provide a visual diagnosis. The goal is to find any abnormalities in the colon or rectum, namely small growths called polyps. Polyps, found in 20 to 30 percent of patients, usually are benign but can develop into cancer if left untreated.
The procedure, step by step
The day before the procedure:
Patients must consume only clear liquids and follow a prescribed laxative schedule. This is a necessary step because it cleanses the bowels and optimizes the range of vision during the colonoscopy.
The day of the procedure:
Patients go to the exam location, either a hospital or an outpatient facility, where they are placed under anesthesia. Patients can choose to forgo anesthesia, but it is not advised because the colonoscopy can cause severe abdominal cramping during the process.
Once the patient is under anesthesia:
The colon is insufflated (blown up with air) so the colonoscope can pass comfortably through and the doctor can get a clear view of the colon walls, which typically are collapsed. The colonoscope is inserted through the rectum and guided through the colon.
If an abnormality or polyp is discovered:
The colonoscope either removes the polyp completely, which is called a polypectomy, or it extracts a sample from the growth for a biopsy. Any growths that are found are sent to the lab to determine whether the cells are benign, precancerous or cancerous.
Once it's over:
Colonoscopies typically take 20 to 30 minutes. Once completed, the patient is sent to a recovery room until the anesthesia wears off. When the person is awake and alert, he or she can go home but won’t be able to drive or operate heavy machinery until the following day.
Polyps are tested:
Polyps all start as benign, but if they are left untreated, they can develop into cancer. If a polyp containing cancer cells isn’t removed, the cancer eventually will grow into the colon and spread. That usually takes 10 to 15 years from conception of the polyp to the onset of colorectal cancer. When a polyp is tested, it is classified as having low-grade, moderate-grade or high-grade dysplasia, which indicates how far into the cancerous transition the polyp is.
“High-grade dysplasia means the polyp is very close to becoming full-blown cancer,” Dr. Leslie Browder said. “When you remove the polyps, you remove the cancer growing within it.”
Are there side effects?
Colonoscopies can cause mild discomfort but should not cause severe pain. Some residual air may get trapped in the patient’s colon, which can cause gas pains or mild cramping after the procedure. Some patients also may experience headaches, nausea and mild dehydration from the bowel preparation process. Very rarely, in fewer than 0.5 percent of cases, the colonoscope can puncture the bowel.