Best colorectal cancer test for your health, lifestyle revealed

Time for a rear-ality check.

Colorectal cancer rates have been rising among adults younger than 50 since the 1990s, a troubling trend that has perplexed scientists.

Because of the increase in cases, an independent panel of medical experts known as the US Preventive Services Task Force (USPSTF) lowered the recommended age to start screening for colorectal cancer from 50 to 45 for people of average risk.

The USPSTF suggests a range of screening options for adults 45 to 75, including stool-based tests and visual exams such as colonoscopies. Early detection means more treatment options and higher survival rates.

So, how do you know which test is best? Dr. Eric Yoon, a double board-certified gastroenterologist and attending physician at Manhattan Gastroenterology, shares the pros and cons of the various assessments.

Colonoscopy

A gastroenterologist inserts a long, thin, flexible tube with a small, lighted camera into the rectum and guides it through the colon to detect abnormalities, such as precancerous polyps.

During the procedure, the doctor can remove polyps or take tissue samples for further testing. Patients are typically given sedation to minimize discomfort.

While prepping for a colonoscopy can be daunting and messy, as it involves laxatives to clear the bowels, complications from the procedure are rare. The benefits most often outweigh the risks.

“All gastroenterologists’ preference will lean towards colonoscopy,” Yoon told The Post.

“Advantages to colonoscopy include diagnosis and therapy during the same procedure, i.e. see a polyp and remove it on the spot.”

If no abnormalities are found, patients at average risk typically don’t have to get another colonoscopy for 10 years.

Stool-based tests

These tests don’t require bowel preparation or sedation and can be done at home. Poop samples are sent to a lab, which looks for hidden blood and/or abnormal DNA that may indicate cancer or polyps.

“Cologuard and other stool-based tests are advantageous if a patient has significant comorbid medical disease (advanced heart or lung disease or neurologic disability preventing easy mobility to and from the toilet),” Yoon said.

“Other scenarios in which stool testing may be preferred are if busy schedules with children, family or work prevent you from doing bowel preparation and clearing up a few hours of your day to get the procedure done.”

Yoon noted that people who have a history of blood in their poop or symptomatic hemorrhoids are not advised to use a stool collection kit.

There are three main types of stool-based tests — fecal immunochemical test (FIT), guaiac-based fecal occult blood test (gFOBT) and multitarget stool DNA test (sDNA-FIT).

FIT uses antibodies to detect hemoglobin, a protein in red blood cells. In gFOBT, the chemical guaiac is used to find heme, a component of hemoglobin. These two tests typically need to be repeated every year for people at average risk of colorectal cancer.

Cologuard is a prescription sDNA-FIT test, which detects blood in the stool (FIT) and DNA markers associated with colorectal cancer. It should be done every three years.

“Cologuard has better sensitivity and specificity as compared to fecal immunohistochemical testing (FIT) stool testing; however, it is more costly as compared to the FIT test,” Yoon said.

Most health insurance plans, including Medicare, Medicare Advantage and Medicaid, cover Cologuard. Without insurance, it can cost around $600. An FIT can sell for $40 or even less over the counter.

A positive stool test typically leads to a colonoscopy to confirm the finding.

The rest

A flexible sigmoidoscopy is like a colonoscopy, except that it only explores the rectum and the lower part of the large intestine, known as the sigmoid colon, instead of the entire colon.

Yoon noted that polyps can be removed during a sigmoidoscopy, which is often performed without sedation — but the examination is limited. Rare but possible complications include infection and a tear in the colon wall.

In a virtual colonoscopy, a CT scanner visualizes the colon and rectum. It’s a non-invasive procedure that still requires bowel prep, like a traditional colonoscopy, to ensure clear images.

It might be a good option for people who cannot tolerate a colonoscopy, but this technique may miss smaller, flatter lesions, Yoon said. A follow-up colonoscopy is required for positive findings.

And finally, the Food and Drug Administration has approved blood-based colorectal cancer tests for people 50 and over who decline to undergo other screening methods.

The good news is that they don’t require bowel prep or sedation.

The bad news is that these tests are generally not considered first-line screening methods in US guidelines due to their limitations in sensitivity, particularly for advanced polyps. 

“That being said, any test that gets done is better than no test at all,” Yoon said. “The decision on the modality of screening should be made as a collaborative discussion with the patient.”