Colon polyps are small clumps of cells that grow inside your colon. They are common, especially after age 45, and usually harmless. However, some polyps can develop into colon or rectal cancer over time. Understanding colon polyps, including their cause, types, risk factors, and treatment, can help you be better prepared if you have any.
Causes of Colon Polyps
Healthy colon cells grow and die as they should. However, if DNA changes occur, colon cells can start to divide too often, forming polyps.
Most experts believe environmental factors and family history contribute to an increased risk of developing polyps. While you can't change your genetics, healthier lifestyle choices can help lower the risk. Smoking, obesity, alcohol consumption, and eating a high-fat, low-fiber diet are all associated with polyp formation.
Types of Colon Polyps
There are five main types of colon polyps. The type of polyp is classified after the tissue is removed during a colonoscopy and examined under a microscope. These types include:
- Adenomatous: This is the most common type, accounting for about 70% of all colon polyps. They can become cancerous over time.
- Villous Adenoma: This type accounts for about 15% of all polyps and is more likely to be cancerous. Polyps of this type are typically flat, making them more difficult to remove.
- Sessile Serrated: These polyps can become cancerous and are usually precancerous when found. The larger-sized serrated polyps in the upper colon tend to be harder to detect.
- Hyperplastic: These quick-growing polyps typically remain small and are usually not cancerous.
- Inflammatory: These are usually only found in people with an inflammatory bowel disease (IBD) and are unlikely to become cancerous. They are not technically polyps but rather inflammation caused by IBD.
What Risk Factors Contribute to Polyp Growth?
Anyone can develop polyps. However, certain factors increase the likelihood of this happening, including:
- Being older than 45 years old. About half of all adults have polyps.
- Family history of colon cancer or polyps (even non-cancerous polyps)
- Your race. Colon cancer risk is higher in black people compared to white people.
- Having genetic abnormalities (Lynch syndrome, familial adenomatous polyposis, serrated polyposis syndrome, and others) can cause polyps to form.
- Having inflammatory intestinal conditions such as ulcerative colitis or Crohn's disease
- Not exercising regularly
- Eating an unhealthy, high-fat diet or a diet high in red meat
- Being obese
- Being a smoker, especially when combined with alcohol
- Drinking three or more alcoholic drinks a day
Detecting Colon Polyps
Most polyps are detected during colon cancer screening. A colonoscopy is an outpatient screening procedure performed by a gastroenterologist. A flexible tube with a camera attached is inserted into the rectum and moved into the colon. Patients are given medicine to relax during the procedure so the doctor can examine the colon for polyps. If any suspicious polyps are found, they are removed during the procedure and then sent in for testing.
Colonoscopies are critical to regular colorectal cancer screening starting at age 45. If you have a family history or other risk factors for developing colorectal cancer, it's important to discuss screening at an earlier age with your doctor.
Related Read: Colon Cancer Screening Age Lowered to 45
While most polyps are not cancerous, finding them early is best. If cancer is found, it’s most likely at an early stage when treatment and recovery are much easier.
In addition to colonoscopies, other tests may be used based on your history and health condition.
- Flexible sigmoidoscopy: This test uses a flexible tube to check the lower third of your colon for polyps. Polyps in the top two-thirds of your colon cannot be checked with this method.
- Virtual colonoscopy: This test uses a CT scan to check your colon from outside your body, but the bowel must be cleared like a regular colonoscopy. If abnormalities are found, a colonoscopy will be needed to remove them.
Are At-Home Stool Tests Accurate for Finding Polyps?
You’ve likely heard about at-home stool tests such as Cologuard®. They are popular because they offer privacy and convenience. The test involves sending a stool sample to a lab to check for blood and analyze DNA for signs of cancer. However, these tests cannot confirm if a polyp is the cause of blood in the stool. If there are signs of blood or cancer, your doctor will request you go in for a colonoscopy so they can find the source.
Read our blog: 5 Important Things You Need To Know About Colorectal Cancer and At-Home Tests
Should I Worry About Cancer if a Polyp Is Found?
Most polyps are harmless, but their size can influence the likelihood of cancer developing. The majority of polyps are between 1 and 9 millimeters (mm) in size. According to a 2018 study published by the American Journal of Gastroenterology, only 3.4% of polyps in this size range were found to be cancerous. However, for polyps 10mm or larger, the cancer rate jumps to 13.4%.
This highlights the importance of colonoscopies for colon cancer screening, starting at age 45. By removing smaller polyps, the risk of cancer development is reduced.
Do Polyps Cause Symptoms?
Most people with polyps don’t experience symptoms, which is why regular screenings are important. However, larger polyps can cause the following symptoms:
- Blood or mucus in your stool
- Rectal bleeding
- Changes in normal bowel habits, such as constipation or diarrhea lasting longer than a week
- Unexplained weight loss
- Changes in stool color, such as red streaks or black stools
- Pain or stomach cramps caused by large polyps partially blocking the bowel
- Anemia, resulting from chronic bleeding from polyps, which can lead to fatigue and shortness of breath
Treatment for Colon Polyps
Polyps are typically removed painlessly during a colonoscopy through a polypectomy procedure. The two most common removal methods are using a wire loop to cut off the polyp or employing an electrocautery device to burn through the polyp's base.
After polyp removal, follow-up care may be necessary depending on the type of polyp:
- Small hyperplastic polyps in the lower colon typically do not require follow-up until the next colonoscopy in 10 years.
- Hyperplastic polyps in the upper colon usually require more frequent repeat colonoscopies.
- Adenomatous polyps require a repeat colonoscopy. Timing is based on the number of polys, their size, and their appearance.
- Patients with a personal or family history of polyps have a higher risk of developing new ones. Those who have had an adenoma have a 30% to 40% risk of recurrence within three years.
If the polyps found during a colonoscopy are large or pose a risk to the patient, a separate, minimally invasive surgical procedure may be needed.
My Biopsy Confirmed a Cancerous Polyp: Now What?
The good news is when colorectal cancer is detected early during a screening colonoscopy, it is usually at a very early stage and highly treatable. If a polyp biopsy determines the presence of colon cancer, schedule an appointment with a colon cancer specialist at Virginia Oncology Associates. We are here to answer your questions and create a colorectal cancer treatment plan tailored to your specific needs. We also offer second opinions as you start making decisions.
Virginia Oncology Associates has several locations throughout Virginia and Eastern North Carolina, including Chesapeake, Elizabeth City, Hampton, Newport News, Norfolk, Suffolk (Obici and Harbour View), Virginia Beach, and Williamsburg.
