Is Colon Cancer Screening Just a Scam?

Whenever you see lots of advertising, or hear something frequently, it means there is ample money in it. Thus, screening for cancer is important. All stress how essential it is to search for cancers. The idea is to find a cancer when it is small, and then be able to remove it entirely before it spreads all over the body. Screening for colon cancer is especially promoted. People are being pushed and even bullied into getting a colonoscopy. The risks and benefits are not discussed, or if it is an option, but rather forced into the procedure.

So, I would like to present you with what a doctor should give you to make a wise decision for yourself.

What is a Colonoscopy?

A colonoscopy is putting a long fiberoptic camera through the anus into the rectum for the doctor to visually see the colon. It requires a cleanse called a “bowel prep” to make sure the colon is “squeaky-clean.” This allows the doctor to see the lining of the colon, and any polyps that might be there. If there are any “suspicious lesions,” the doctor can remove them or do a biopsy and send them to the pathologist to determine if there is cancer.

When doctors recommend colonoscopy, they generally quote the benefits without acknowledging the risks, so we will address the risks.

COLONOSCOPY RISKS

Colonoscopy does not see all lesions because not all are apparent. A good colonoscopist will miss about 30% of the lesions. Some miss over 60%!  Colonoscopy is thus an incomplete test.[1] This leads to about 9% of those screened by a colonoscopy developing colorectal cancer in the ten years before their next test.[2] That’s about equivalent to the general population.

There is only one prospective randomized trial comparing colonoscopy to doing nothing. Last year, The New England Journal of Medicine published a European trial of colonoscopy that showed an 18% decreased risk of dying from colon cancer in the population offered screening, but the overall death rate stayed the same.[3] There is no evidence that colon cancer screening will lower the overall mortality, so you should not be told, “It could save your life.”

What’s worse is that the procedure itself has risks. Serious complications include bleeding and perforation with infection in the abdomen, which seems to be around 28 per ten thousand colonoscopies performed.[4]  The chances of harm from the procedure are not small. Serious bleeding can occur from removing a polyp, about 50 per ten thousand, depending on the study. And death from perforation is around 5 per ten thousand.[5] If you consider the low rate of colon cancer, these complications are significant.

It is important that you understand the numbers. Colon cancer is not a big cause of death. The overall odds of dying from colon cancer are one in ten thousand in the United States[6] It requires over a thousand screening colonoscopies to find one cancer. Moreover, three colon cancers are diagnosed for everyone who dies from the disease, so most are not deadly. The low rate (3.6 per ten thousand) of this cancer makes screening difficult. Therefore, the death rate from colonoscopy is significantly higher than the death rate from colon cancer. Screening for colon cancer has not changed the death rate from colon cancer over the population. In fact, it’s increasing.

Other complications are not from the test, but from the bowel cleanse or anesthesia administered for the test. I have had several patients with bowel prep issues, including chronic diarrhea afterwards.

Thus, it may be riskier to do the test than to get the cancer. The bottom-line is there is risk to the procedure that is greater than the potential or tested benefits. If you are going to get a colonoscopy, you may need to determine if this is valuable. For example, if you have bleeding, colitis, hereditary polyposis, Lynch syndrome, obstruction, or some other colon abnormality, you may need a colonoscopy. Doing a diagnostic colonoscopy is useful because though the risks are still there, they are clearly worth the benefits. However, screening healthy people is riskier because there is so little benefit.

OTHER HELPFUL TESTS

There is no good test that detects most colorectal cancers. Even though colonoscopy misses about 50% of cancers, it is still considered the standard of screening tests for colon cancers. However, there are other types of tests that might be appropriate. They include: