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.
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.
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.
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.
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.
Most colon polyps are harmless. But over time, some colon polyps can develop into colon cancer, which may be fatal when found in its later stages. Anyone can develop colon polyps.
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.
Most polyps grow slowly and take from between 10 and 15 years to become cancerous.
Anywhere between 15 and 40 percent of adults may have colon polyps. Colon polyps are more common in men and older adults.
They can occur anywhere in the large intestine or rectum, but are more commonly found in the left colon, sigmoid colon, or rectum.
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.
A polyp can take as many as 10 to 15 years to develop into cancer. With screening, doctors can find and remove polyps before they have the chance to turn into cancer.
The risk of polyps smaller than 5 millimeters (mm) being cancerous is very low. In larger polyps, the risk of cancer increases. Colon polyps grow very slowly and often do not cause symptoms. Regular colon cancer screenings can help detect them before they become cancerous.
Most colorectal cancers start as polyps, however, not all polyps turn into cancer. A doctor will often remove polyps once they are detected, usually during a colonoscopy. They will usually send these polyps off for a biopsy to test them for cancer.
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.
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.
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.
Living with polyps
Treatment provides a good outlook. If you do not get your polyps removed, they can continue to grow. They may develop into cancer. If you've had polyps before, you are at greater risk of getting more.
Adenomas: Many colon polyps are the precancerous type, called adenomas. It can take seven to 10 or more years for an adenoma to evolve into cancer—if it ever does. Overall, only 5% of adenomas progress to cancer, but your individual risk is hard to predict.
If a polyp has cancerous cells, they will also biopsy nearby lymph nodes to determine if the cancer has spread or metastasized to other areas of the body. In this case radiation, chemotherapy or other therapies may be recommended. Colonoscopy screenings can be life saving!
Colon polyp development involves genetic and epigenetic changes and environmental effectors such as stress in this process can drive the normal colonic epithelial cells to hyperplastic and adenomas [25-27].
Depending on their size and location in the colon, serrated polyps may become cancerous. Small, serrated polyps in the lower colon, also known as hyperplastic polyps, are rarely malignant. Larger serrated polyps, which are typically flat (sessile), difficult to detect and located in the upper colon, are precancerous.
Smoking, obesity, diabetes, and inadequate exercise are risk factors for polyps, but many people with none of these risk factors have precancerous polyps in the colon. There are genetic risk factors for developing polyps as well.
Colon polyps are clumps of cells that form in the lining of the colon. They grow slowly over time and typically do not cause symptoms, particularly when they are small.