A gastroenterologist, the specialist who usually performs a colonoscopy, can't tell for certain if a colon polyp is precancerous or cancerous until it's removed and examined under a microscope.
The only way to be sure that a colon polyp has cancer is to remove the polyp and look at it under a microscope. But a colonoscopy may show some signs that there may be cancer.
It's a clump of cells that are growing abnormally. A polyp is usually shaped one of two ways. It can be a flat bump (sessile). Or it can be shaped like a mushroom, with a bulbous head projecting from a stalk (pedunculated).
Colon Cancer Diagnosis: Getting a Colonoscopy
Screening is crucial for cancer detection because most colorectal cancers don't cause symptoms in the early stages. Many times, doctors first spot colon cancer during a routine screening colonoscopy.
Before you go home, your doctor tells you if they removed any growths (polyps) or tissue samples (biopsies) from your bowel. The biopsy results can take up to 2 weeks. Your specialist writes to you with the results. If your GP referred you for the test, they should also receive a copy.
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.
However, it will take some time to receive your test results from the lab that will confirm or rule out cancer. Your doctor may have some information for you prior to the lab test results, but the official results will come from the lab within a couple weeks.
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.
Approximately 6% of colorectal cancers are diagnosed within 3 to 5 years after the patient received a colonoscopy, according to findings from a recent population-based study.
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.
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.
If the polyps are larger (10 mm or larger), more numerous, or abnormal in appearance under a microscope, you may have to return in three years or sooner. If the exam finds no polyps, "your cancer risk is essentially the average for the population, and you can wait 10 years for the next screening," Dr. Saltzman says.
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.
Why is a polyp biopsy performed? Most polyps are benign, or noncancerous. However, since polyps are caused by abnormal cell growth, they can eventually become cancerous. Your doctor may want to perform a polyp biopsy to determine whether the growth is cancerous or benign.
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 gastroenterologist, the specialist who usually performs a colonoscopy, can't tell for certain if a colon polyp is precancerous or cancerous until it's removed and examined under a microscope.
Results: Mean number of initial polyps were 2.2 and advanced polyps were observed in 40% of the patients. The cumulative recurrence rate of colon polyp was 13.8% within 1 year, and 60% within 3 years, while that of advanced polyps was 2.5% and 31% within 1 and 3 years, respectively.
Colonoscopies can detect conditions like colitis, inflammatory bowel disease and diverticulosis. But mainly, doctors are looking for precancerous or cancerous colon polyps, which are growths on the inside of the colon's lining.
It could take 2 to 3 days before you have a bowel movement after your colonoscopy because you completely emptied your colon and rectum ahead of the procedure. You may notice a little bit of blood in your first stool after your colonoscopy, especially if your doctor removed a polyp or took a biopsy of abnormal tissue.
“The physician may do a CT scan of the abdomen, pelvis and chest to look for any metastasis and will determine the approach to surgery and different therapies from there.” For most colorectal cancers, treatment will include surgical removal.
However, over time polyps can become large and malignant if they aren't treated. Many polyps are found to be pre-cancerous, which means they have the potential to turn cancerous if they aren't removed. With early detection through an endoscopic test, the risk can be eliminated by your gastroenterologist.
"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."
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.
A polypectomy lasts about 30 to 60 minutes and is an outpatient procedure, allowing patients to return home the same day. They should be back to a normal routine as soon as the next day.