July 15, 2025
Are Colon Polyps Cancerous?
A colon polyp is a small growth that forms inside the colon, attached to the colon wall. Polyps are common and usually harmless in most adults. However, some polyps can eventually develop into colon or rectal cancer. Understanding colon polyps can help you prepare for what comes next if any are detected during a routine screening.
How Do Colon Polyps Form?
Cells within a healthy colon go through a regenerative life cycle, meaning they replace themselves over time. However, changes in DNA can cause the cells to start reproducing incorrectly, leading to rapid cell division, which can lead to the development of colon polyps.
Experts believe that environmental factors, lifestyle choices, and family history all influence whether a person will develop colon polyps. While genetics cannot be controlled, some other factors can. Adopting healthy habits, including quitting smoking, limiting alcohol consumption, and eating a balanced, nutritious diet, can help prevent the formation of colon polyps.
Types of Colon Polyps
After tissue is removed during a colonoscopy, it is examined under a microscope and classified into one of five types of polyps:
Adenomatous Colon Polyps: These account for about 70% of all colon polyps and are the most common type. Adenomatous polyps have the potential to become cancerous over time.
Villous Adenoma Colon Polyps: Representing about 15% of all polyps, this type is more likely to be cancerous and may be more challenging to remove due to its flat shape.
Inflammatory Colon Polyps: These are caused by inflammatory bowel disease (IBD) and are not true polyps. They are usually found in people with IBD and are unlikely to become cancerous.
Hyperplastic Colon Polyps: These polyps tend to grow quickly, stay small, and do not become cancerous.
Sessile Serrated Colon Polyps: These polyps are typically precancerous when found, but can become cancerous. Larger serrated polyps in the upper colon are often harder to detect.
Are There Risk Factors Associated With Polyp Growth?
While anyone can develop polyps, certain factors can increase your risk, including:
Being older than 45
Having a family history of colon cancer or non-cancerous polyps
Not exercising regularly
Being obese
Smoking
Being African American
Drinking excessive amounts of alcohol
Eating a diet high in fat, processed foods, and red meat
Having inflammatory intestinal conditions, like ulcerative colitis or Crohn's disease
Having a genetic condition such as Lynch syndrome, familial adenomatous polyposis, or serrated polyposis syndrome, known to cause polyp formation.
No one is immune to developing colon polyps, but making positive lifestyle adjustments can help lower your risk of colon polyps and colorectal cancer.
How Are Colon Polyps Detected?
Most polyps are found during colon cancer screening, typically with a colonoscopy. This procedure allows your doctor to look closely inside the colon for polyps. Any suspicious polyps found are removed during the procedure and sent in for testing.
The earlier colon or rectal cancer is detected, the better the chances of successful treatment. Average-risk individuals are advised to start screening at age 45 to manage their colon and rectal health proactively. Anyone with a family history or known risk factors for colorectal cancer should talk to their doctor about screening earlier than the recommended age. Read more about when you should start colon cancer screenings.
Are At-Home Stool Tests Reliable for Detecting Polyps?
At-home stool tests like Cologuard® are becoming increasingly popular due to their privacy and convenience. These tests allow you to collect a stool sample at home and send it to a laboratory, where they check for the presence of blood. Some newer tests also analyze your DNA for signs of cancer. However, a disadvantage of these tests is that they cannot confirm whether a polyp is the source of these signs. Therefore, a colonoscopy is necessary to identify the exact cause.
Related reading: What You Need to Know About At-Home Colon Cancer Testing
Should I Assume I Have Cancer if a Polyp Is Found?
Most polyps are harmless, but the larger they become, the more likely they are to become cancerous. A study published in the American Journal of Gastroenterology found that only 3.4% of polyps measuring between 1 and 9 millimeters were cancerous. However, for polyps measuring 10 mm or larger, the rate of cancer increased to 13.4%.
Getting screened with a colonoscopy starting at age 45 allows for the detection and removal of polyps while they are still small.
Are There Symptoms Caused By Polyps?
Not all colon polyps cause symptoms, which is why regular screening is crucial. However, if polyps reach a certain size, they may lead to symptoms such as:
Bleeding from the rectum
Stool containing blood or mucus
Changes in stool color, including red streaks or black stools
Unusual bowel habits, such as constipation or diarrhea lasting more than a week
Unexplained weight loss
Stomach pain or abdominal cramps caused by large polyps that partially block the bowel
Anemia due to chronic bleeding, which can lead to fatigue and shortness of breath
How Colon Polyps Are Treated
Doctors often perform a polypectomy procedure during a colonoscopy to remove polyps painlessly. This technique involves cutting the polyps off with a wire loop or destroying them using an electrocautery device.
In some cases, surgery may be necessary if polyps are large or pose a risk of being removed during the colonoscopy. Minimally invasive surgery can be performed using a laparoscope through a small incision in the abdomen.
Depending on the type of polyp removed, follow-up care may be necessary:
Hyperplastic polyps in the upper colon often require more frequent repeat colonoscopies.
Patients with a personal or family history of polyps are at an increased risk of developing new ones. Those with adenoma have a 30% to 40% risk of recurrence within three years.
Small hyperplastic polyps in the lower colon often don’t require follow-up until the next colonoscopy in 10 years.
Adenomatous polyps require a repeat colonoscopy, the timing of which depends on the polyp’s size, number, and appearance.
Your doctor will consider these factors when determining a suitable screening schedule.
What To Do After Being Diagnosed With a Cancerous Polyp
Fortunately, colorectal cancer detected early during a screening colonoscopy is generally at a very early stage and highly treatable. If a polyp biopsy indicates the presence of colon or rectal cancer, the next step is to consult with a medical oncologist who specializes in treating colorectal cancer.
The oncologists at Cancer Care Centers of Brevard are experienced in various aspects of colon and rectal cancer treatment, including clinical trials that give patients access to new therapies. Make an appointment at one of our cancer centers located throughout the Space Coast, including Palm Bay, Melbourne, Merritt Island, and Rockledge, FL.
Categories: Colorectal Cancer