Diagnosing and Treating Colon Polyps: What You Need to Know

Colon polyps are small growths that develop on the lining of the large intestine, and while many are harmless, some can potentially turn into colorectal cancer if left untreated. Larger polyps require special attention as they carry a higher risk of becoming cancerous.

What Are Large Colon Polyps?

According to Dr. Kais Zakharia, advanced endoscopist, Division of Gastroenterology/Hepatology at Baystate Health, “Large colon polyps are abnormal growths that develop on the inner lining of the colon or rectum and are typically larger than 1 centimeter in size. They account for about 5% of all colon polyps found during colonoscopies. While the majority of large colon polyps are benign, meaning they are not cancerous, some have the potential to become cancerous over time.”

How Large Colon Polyps Are Diagnosed

One of the challenges of polyps of any size is that they’re often asymptomatic (meaning they have no symptoms), especially when small. By the time symptoms, such as bleeding or changes in bowel habits, appear the polyp is likely very large and challenging to treat.

This is why, Dr. Zakharia says, screening is so critical. He notes, “Screening is the best way to prevent polyps from turning to cancer.”

Currently there are several methods for screening for polyps: colonoscopy, imaging and stool tests.

Colonoscopy

Colonoscopy is widely considered the best way to detect and diagnose large colon polyps. During a colonoscopy, the doctor uses a long, flexible tube, called an endoscope, with a camera attached to visually inspect the entire colon and rectum. If any polyps are found, they can often be removed during the same procedure.

Dr. Zakharia emphasizes that healthy individuals with no personal or family history of colon cancer should have their first colonoscopy at age 45. People with a family history of colon cancer should begin receiving colonoscopy earlier (usually at age 40).

Stool Tests

Stool tests- where the patient collects fecal material at home and sends it in to a lab to be tested - are used to find possible signs of colorectal cancer or polyps. Dr. Zakharia adds, “Because they can be done at home and don’t require anesthesia, many people consider them easier than a colonoscopy. But these tests are only diagnostic. If the test identifies an abnormality, you still need to have a colonoscopy to treat it.”

Treatment: Options for Removing Colon Polyps

While the notion of a polyp in your colon sounds alarming, Dr. Zakharia emphasizes this point: “Most polyps, no matter how big, can be removed endoscopically without a need for surgery unless there is advanced cancer.”

There are several endoscopic techniques available to remove large colon polyps. “The choice of technique depends on the size, location, and characteristics of the polyp,” says Dr. Zakharia. “We share the options, risks, and potential outcomes with each patient and allow them to decide which is right for them.” He also notes that while a plan is created prior to surgery, “Plans can change during the procedure.”

He explains, “There are a lot of variables that we don’t know until we actually get in and look at the polyp. So, while we might determine in advance that we want to use one procedure, the position, shape or general nature of the polyp may force us to use a different technique. Regardless of the tools or approach used, the goal is always to completely remove the polyp without adversely affecting the normal tissue.”

Here’s a look at the most common techniques for removing polyps:

Endoscopic Mucosal Resection

The most common method for removing polyps, this technique can usually be accomplished in under an hour. It involves injecting a solution under the polyp to lift it from the muscle layer of the colon wall. A small wire snare is then looped over the elevated polyp. The snare is drawn tight and electrical current is used to cut away the polyp. In the best cases, the entire polyp is removed at once. But in the case of larger polyps, the polyp may need to be removed in multiple pieces.

“While EMR is very safe and usually very quick, the recurrence rate for polyps can be rather high as it is not always possible to remove the entire polyp—especially when it’s removed in multiple pieces,” says Dr. Zakharia.

Endoscopic Submucosal Dissection (ESD)

The preferred technique for large polyps, ESD uses a blade to remove larger lesions in one piece, reducing the risk of leaving behind any polyp tissue. The ability to remove the entire polyp is important as it allows for accurate evaluation and staging of any cancer, which is important for determining if the resection was complete and curative. Because the polyps being removed with ESD are larger and often in challenging locations to reach, it’s not uncommon for ESD procedures to last several hours.

Hybrid ESD

As the name suggests, hybrid ESD involves a combination of techniques for removing polyps. Dr. Zakharia explains, “In this type of procedure, both the snare and a knife are used to remove the polyp and any suspicious tissue. The advantage is you still get majority of the polyp in single piece, but the procedure is faster than a traditional ESD.”

Endoscopic Full Thickness Resection (EFTR)

Unlike EMR and ESD that are limited to superficial layers of colon wall, EFTR allows for the removal of polyps that penetrate through the full thickness of the colon wall. In the past, these challenging types of polyps required major surgery and lengthy hospital stays. Performed endoscopically, EFTR uses an almost claw-like device to resect (cut out) the entire thickness of the colon wall while leaving a clip in place to close the defect. While EFTR can only remove small polyps, its ability to remove questionable tissue without major surgery makes it a true game changer for patients requiring the procedure.

What to Expect After a Polyp Procedure

Thanks to the non-invasive nature of endoscopic procedures, most patients go home the same day and are able to resume normal activities and enjoy their usual diet.

It typically takes a few days to receive the lab report on the extracted tissue. In cases where cancer is detected, the patient is contacted by their doctor and referred to either a medical or surgical oncologist or both to determine next steps.

All patients, regardless of the lab findings, are encouraged to have a follow-up colonoscopy. For patients who underwent an EMR, a colonoscopy is recommended 6 months after the procedure and 12 months after for those who had an ESD.

Dr. Zakharia adds, “We advise all patients under the age of 60 who have large polyps to advise their family members of the finding. This allows other individuals to schedule their first colonoscopy sooner than age 45 and improves their chance for a better outcome if a polyp is found.”

Colon Polyp and Colon Cancer Prevention

While there is no known way to prevent colon polyps, there are things you can do to reduce your risk of developing them. These include:

• Eat a diet low in fats and red meats and rich in fruits, vegetables, and fiber
• If you’re obese, lose weight
• If you smoke, quit. If you don’t smoke, don’t start
• Limit alcohol use
• Get your colonoscopy on time as recommended by your primary care provider

“The best way to prevent a polyp from turning cancerous is to catch it early,” says Dr. Zakharia. “Many people who were hesitant to get a colonoscopy are often surprised how ‘not unpleasant’ the procedure is. The most challenging part is really the prep. But you weigh the few hours of inconvenience against the potential of allowing a polyp to develop into colon or rectal cancer—the second-leading cause of cancer deaths in the U.S.—it’s an easy decision to make.”