Bowel polyps are small growths on the inner lining of the large intestine (colon) or rectum. Bowel polyps are very common, affecting around 1 in 4 people aged 50 or over. They're slightly more common in men. Some people develop just 1 polyp, while others may have a few.
Bowel polyps are not usually cancerous, although if they're discovered they'll need to be removed, as some will eventually turn into cancer if left untreated. Some people just develop one polyp, while others may have a few. They tend to occur in people over the age of 60.
Polyps are one of the most common colorectal conditions, occurring in 15 - 20 percent of the adult population. They can occur anywhere in the large intestine or rectum, but are more commonly found in the left colon, sigmoid colon, or rectum.
He says you might be surprised how often colonoscopies uncover polyps lurking in your colon. "Precancerous polyps are extremely common," he says. "We expect to find them in more than a quarter of the colonoscopies that we do at a minimum.
Here's what we know: As often as 40% of the time, a precancerous polyp — frequently a type called an adenoma — is found during a screening colonoscopy. Colon cancer is found during only in about 40 out of 10,000 screening colonoscopies, Dr. Sand said.
Anywhere between 15 and 40 percent of adults may have colon polyps. Colon polyps are more common in men and older adults.
A polyp is a small growth of excess tissue that often grows on the lining of the large intestine, also known as the colon. Colon and rectal polyps occur in about 25 percent of men and women ages 50 and older.
Most colorectal cancers start as a growth on the inner lining of the colon or rectum. These growths are called polyps. Some types of polyps can change into cancer over time (usually many years), but not all polyps become cancer. The chance of a polyp turning into cancer depends on the type of polyp it is.
Polyps are common in American adults, and while many colon polyps are harmless, over time, some polyps could develop into colon cancer. While the majority of colon cancers start as polyps, only 5-10% of all polyps will become cancerous.
A polyp is the result of genetic changes in the cells of the colon lining that affect the normal cell life cycle. Many factors can increase the risk or rate of these changes. Factors are related to your diet, lifestyle, older age, gender and genetics or hereditary issues.
Aging — Polyps and colorectal cancers are uncommon before age 40. Ninety percent of cases occur after age 50, with males somewhat more likely to develop polyps than females; therefore, colon cancer screening is usually recommended starting at age 50 for both sexes.
How long does it take for a polyp to turn into cancer? The growth and mutation of colon polyps into cancer is a slow process, taking an estimated 10 years on average. So as long as patients are screened, it is unlikely they will develop cancerous polyps.
Most polyps are benign (not cancerous). Your doctor can tell if a colon polyp is cancerous during a colonoscopy by collecting tissue to biopsy. The results of the biopsy are typically sent to your doctor within a week. Only 5% to 10% of all polyps become cancerous.
Common Symptoms of Colon Polyps
Changes in Bowel Movements – Sometimes colon polyps can lead to constipation or diarrhea that persists for longer than a week, as well as general changes in bowel habits.
Most polyps grow slowly and take from between 10 and 15 years to become cancerous.
In multivariable analysis, the presence of 5 or more polyps at index colonoscopy was found to be associated with the risk of metachronous HR-CRN (OR, 2.575, p = 0.049) after adjusting for risk factors, such as obesity, diabetes, and smoking.
The doctor will then send any removed polyps to a pathologist for a biopsy to see if cancer is present. If the biopsy reveals that cancer is present, then cancer specialists will outline a treatment plan for the person. Common treatments for colon cancer include surgery, chemotherapy, and radiotherapy.
If they found precancerous cells, there is no need for any additional treatment as long as they removed the entire polyp. Removing the tissue stops the development of cancer. Since you are still at an increased risk, we will likely recommend repeating the screening every three to five years in the future.
"Precancerous polyps are extremely common," he says. "We expect to find them in more than a quarter of the colonoscopies that we do at a minimum. So, you know, maybe a third or even a half of all patients getting [a] colonoscopy will have precancerous polyps."
If the colonoscopy finds one or two small polyps (5 mm in diameter or smaller), you are considered at relatively low risk. Most people will not have to return for a follow-up colonoscopy for at least five years, and possibly longer.
*For screening, people are considered to be at average risk if they do not have: A personal history of colorectal cancer or certain types of polyps. A family history of colorectal cancer.
Cancers can “run in the family” because of inherited genes, shared environmental factors, or some combination of these. Having family members who have had adenomatous polyps is also linked to a higher risk of colon cancer. (Adenomatous polyps are the kind of polyps that can become cancer.)
Colon polyps are extremely common among adults 50 years of age and older, occurring in over 40 percent of individuals who undergo screening colonoscopy.