Colorectal cancer is the third most common cancer type worldwide; in 2020, almost 2 million cases were diagnosed. It is the second most common cause of cancer death, leading to almost 1 million deaths per year. This is despite the fact that effective screening techniques exist that could reduce the number of deaths from this disease.
USPSTF - United States Preventative Services Task Force Recommendation
May 18, 2021
Colorectal cancer is the third leading cause of cancer death for both men and women, with an estimated 52 980 persons in the US projected to die of colorectal cancer in 2021. Colorectal cancer is most frequently diagnosed among persons aged 65 to 74 years. It is estimated that 10.5% of new colorectal cancer cases occur in persons younger than 50 years. Incidence of colorectal cancer (specifically adenocarcinoma) in adults aged 40 to 49 years has increased by almost 15% from 2000-2002 to 2014-2016. In 2016, 26% of eligible adults in the US had never been screened for colorectal cancer and in 2018, 31% were not up to date with screening.
As seen below, the recommendation to screen adults aged 50 to 75 years old has substantial benefit where adults aged 45-49 likely has moderate benefit. Recent reports of well-known actors that passed from colon cancer have put a spotlight on the phenomenon seen above that 10.5% of new colorectal cancers are diagnosed in persons younger than 50 years old.
All recommendations receive a letter grade. These grades reflect the potential benefit of screening. When the Task Force recommends an intervention (Grade A), it is because it has substantially more potential benefits than potential harms for the population covered by the recommendation. When the evidence shows that a screening test may have at least a small benefit for some individuals in the population, but not necessarily everyone, the Task Force gives it a Grade C.
What kind of screening is right for me?
There are multiple acceptable colon cancer screening options in someone who doesn't have a personal or family history of colon CA. See below. Note that if any of the noninvasive testing is abnormal, the next step would be a colonoscopy. The FIT testing may appear to have a lower sensitivity but if it is done yearly, the sensitivity increases. I think both the FIT and the Cologuard are great options.
gFOBT or FIT: every year ($20, 75% sensitive)
gFOBT uses the chemical guaiac to detect blood in the stool. It is done once a year. For this test, you receive a test kit from your health care provider. At home, you use a stick or brush to obtain a small amount of stool. You return the test kit to the doctor or a lab, where the stool samples are checked for the presence of blood.
FIT uses antibodies to detect blood in the stool. It is also done once a year in the same way as a gFOBT.
sDNA-FIT: every 1 to 3 years (Cologuard) (around $500, 91% sensitive)
The FIT-DNA test (also referred to as the stool DNA test) combines the FIT with a test that detects altered DNA in the stool. For this test, you collect an entire bowel movement and send it to a lab, where it is checked for cancer cells. It is done once every three years.
CT colonography: every 5 years (around $350, >90% sensitive, bowel cleansing required)
Computed tomography (CT) colonography, also called a virtual colonoscopy, uses X-rays and computers to produce images of the entire colon, which are displayed on a computer screen for the doctor to analyze.
Flexible sigmoidoscopy: every 5 years, or every 10 years with FIT every year (around $500, >95% sensitivity, bowel cleansing required)
For this test, the doctor puts a short, thin, flexible, lighted tube into your rectum. The doctor checks for polyps or cancer inside the rectum and lower third of the colon. Not easily accessible in Maine
Colonoscopy: every 10 years (around $2500) (>95% sensitivity, bowel cleansing required)
This is similar to flexible sigmoidoscopy, except the doctor uses a longer, thin, flexible, lighted tube to check for polyps or cancer inside the rectum and the entire colon. During the test, the doctor can find and remove most polyps and some cancers. Colonoscopy also is used as a follow-up test if anything unusual is found during one of the other screening tests. For patients with a family history of colon CA, we only suggest colonoscopy. Also, if any noninvasive techniques screen positive, the next step would be colonoscopy.
With all these different choices, it can be hard to determine what the best approach to screening might be. The truth is, that is a personal decision. Here is what we know, Please consider an office visit to discuss your personal situation.