Almost all precancerous polyps found during colonoscopy can be completely removed during the procedure. Various removal techniques are available; most involve removing them with a wire loop or biopsy forceps, sometimes using electric current. This is called polyp resection or polypectomy.
In most cases, only a polypectomy and/or a local excision is needed to treat this stage of cancer. A polypectomy or local excision involves removing the polyp in its entirety during a colonoscopy. Additional treatment may be needed if a polyp or tumor is too big to be removed through local excision.
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).
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.
A colon polyp is a small clump of cells that forms on the lining of the colon. 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.
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.
Although malignant sessile colon polyps usually require colectomy for proper treatment, the vast majority of malignant pedunculated polyps can be removed colonoscopically for cure.
They can occur anywhere in the large intestine or rectum, but are more commonly found in the left colon, sigmoid colon, or rectum.
Rarely, a polyp will be too large to remove during colonoscopy, which means that a surgical procedure will be needed at a later time. Complications — Polypectomy is safe although it has a few potential risks and complications. The most common complications are bleeding and perforation (creating a hole in the colon).
While the majority of colon cancers start as polyps, only 5-10% of all polyps will become cancerous.
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.
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.
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.
If the cancer has not spread and is localized to the colon, then the 5-year survival rate is 91%. However, if the cancer has spread to the nearby tissues or lymph nodes, the 5-year survival rate is 72%. The survival rate drops to 14% if the cancer spreads to distant parts of the body.
A precancerous polyp by itself is not malignant but if left untreated can become cancerous. It is very common for adults to have polyps in their colon. Precancerous lesions can usually be surgically extracted to avoid cancer. There are two types of polyps hyperplastic polyps and adenomatous polyps.
Some types of colon polyps are more likely to become cancerous than others. A doctor who specializes in analyzing tissue samples (pathologist) will examine your polyp tissue under a microscope to determine whether it is potentially cancerous.
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!
All colorectal cancers arise from benign, precancerous polyps, so it's important to remove them before problems grow. Smaller polyps often can be easily removed during a colonoscopy. (That procedure is known as a polypectomy.) They have bigger arteries, and removing them may cause substantial bleeding.
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.
Completely preventable cancer
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.
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.
Cancerous polyps tend to grow slowly. It is estimated that the polyp dwell time, the time needed for a small adenoma to transform into a cancer, may be on average 10 years (17). Evidence from the heyday of barium enema examinations indicates that most polyps do not grow or grow very slowly (18).
Given enough time to grow and develop, some adenomatous polyps can spread into surrounding tissues and infiltrate the two highway systems of the body: the bloodstream and the lymph nodes. This ability to invade and spread, or metastasize, is how we define a cancer.
A polypectomy is a minimally invasive procedure. Most polypectomies don't even require cutting into your body to access the polyp. They can usually be managed internally, with medical instruments passed through the natural openings in your body.