Large polyps are 10 millimeters (mm) or larger in diameter (25 mm equals about 1 inch).
The size of a polyp typically does make a difference. The larger the polyp becomes, the bigger the risk of it developing into colon cancer. That risk increases significantly if the polyp is greater than 10 mm (1 cm); research has shown the larger a colon polyp becomes, the more rapidly it grows.
In general, a rectal or colon polyp is considered complex (also known as “defiant”) if it meets any of the following criteria: Size greater than 2 centimeters. Located in a difficult area or is too flat (sessile) to be removed during a standard colonoscopy.
In general, sessile or pedunculated polyps more than 2 cm in diameter are considered difficult polyps. Certainly, any polyps greater than 3 cm in diameter, or so-called giant polyps, represent the most challenging polyps.
These larger polyps typically occur on the right side of the colon or in the rectum. They account for about 5% of all colon polyps found during colonoscopies. The vast majority of these large growths are benign.
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.
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.
In 1 to 7 years, depending on a variety of factors: The number, size and type of polyps removed; if you have a history of polyps in previous colonoscopy procedures; if you have certain genetic syndromes; or if you have a family history of colon cancer.
After polyps are removed it can take up to a week for the patient to fully recover. During this time, patients should avoid all strenuous activities, which includes lifting anything over five pounds.
Most polyps are benign (not cancerous). “However, many polyps are precancerous [adenomas], which, if they remain in place for over 5 to 7 years, may progress towards a cancer,” says Yale Medicine's Harry Aslanian, MD, a Yale Medicine gastroenterologist.
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.
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.
Approximately 1% of polyps with a diameter less than 1 centimeter (cm) are cancerous. More than one polyp or a polyp that is 1 cm or bigger places you at higher risk for colon cancer. Up to 50% of polyps greater than 2 cm (about the diameter of a nickel) are cancerous.
Most polyps grow slowly and take from between 10 and 15 years to become cancerous.
They look like bumps growing from the inside lining of the bowel protruding out. They sometimes grow on a “stalk” and look like mushrooms. Some polyps can be flat. People can have several polyps scattered in different parts of the colon.
A colonoscopy is the best way to diagnose and prevent bowel cancer. For most people it is a straightforward test. However, as with most medical tests, complications may occur. If you are at average or slightly above average risk of bowel cancer, screening every two years is recommended.
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.
The effects of the sedation could last up to a day, so you should not drive or operate any machinery until the following day. You may feel gassy or bloated for a while after the procedure because of the air that was injected into your intestine during the colonoscopy.
They can occur anywhere in the large intestine or rectum, but are more commonly found in the left colon, sigmoid colon, or rectum.
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.
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.
After a colonoscopy, eat foods that are soft and easy to digest to ease side effects such as bloating or gas. This may include eggs, white toast, and applesauce for breakfast. For lunch or dinner, choices could include lean chicken without skin, mashed potatoes, and soft-cooked carrots.
Larger polyps might be removed during colonoscopy using special tools to remove the polyp and a small amount of the inner lining of the colon in a procedure called an endoscopic mucosal resection. Minimally invasive surgery (laparoscopic surgery).
Sometimes the nature of a polyp can be distinguished based on how it looks during a colonoscopy. But only removal for examination under a microscope by a pathologist can accurately determine if a polyp is precancerous.