While the majority of colon cancers start as polyps, only 5-10% of all polyps will become cancerous. 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.
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.
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.
There is no set size at which a polyp will become cancerous, nor any particular size that is always cancerous. Even among large polyps, the majority are not cancerous.
It takes approximately 10 years for a small polyp to develop into cancer. Family history and genetics — Polyps and colon cancer tend to run in families, suggesting that genetic factors are important in their development.
The removed polyp tissue is checked for cancer by looking at it under a microscope. If cancer cells are found, surgery might be needed because the cancer may have spread beyond the polyp. But if your provider thinks the cancer is only in the polyp that was removed and hasn't spread, you may not need surgery.
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.
Cancerous polyps may cause no symptoms at all. But if you do have symptoms, they depend on where the polyp is located: Colorectal polyps may cause belly pain, constipation, diarrhea or blood in your poop. Stomach polyps may cause nausea, belly pain, vomiting and bleeding.
Most colon polyps are harmless. But over time, some colon polyps can develop into colon cancer. Colon cancer can be fatal when found in its later stages. Anyone can develop colon polyps.
Colon polyps are small growths on the lining of the large intestine (colon). They're usually benign, meaning they won't cause any problems, especially at early stages. However, when they start growing too fast or larger than usual, they could turn into cancer.
Colorectal cancer can occur without polyps, but it is thought to be an uncommon event. Individuals with long-standing inflammatory bowel diseases, such as chronic ulcerative colitis and Crohn's colitis, are at increased risk for developing colorectal cancer that occurs in the absence of obvious polyps.
Colon cancer treatment will depend on how early the cancer is caught. Sometimes, your doctor can remove polyps during a colonoscopy and no further treatment is necessary. Other times, you may need surgery and/or chemotherapy.
It takes approximately 10 years for a small polyp to develop into cancer. Family history and genetics — Polyps and colon cancer tend to run in families, suggesting that genetic factors are important in their development.
Not all polyps will turn into cancer, and it may take many years for a polyp to become cancerous. Anyone can develop colon and rectal polyps, but people with the following risk factors are more likely to do so: Age 45 years and older. A family history of polyps or colon cancer.
Research indicates that as many as 60 percent of polyps may grow back within three years. Also, about 30 percent of patients who've had polyps removed will develop new ones. This is why it is important to talk to the care team about follow-up screening within five years after the polyps are removed.
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.
Right-sided polyps are more likely to develop into cancers — which often grow rapidly and have a higher risk for metastasis, spreading to distant body areas. Right-sided colon cancers also tend to develop from flat polyps rather than the usual mushroom-shaped ones, and are genetically atypical, too.
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.
When a polyp is adenomatous, the color is more likely to be deep red or purple whereas the color of a non-adenomatous lesion tends to be yellow or white.
People with very early colon cancer (stage 1) do not usually need chemotherapy. But this might change after surgery. After your operation, a specialist doctor (pathologist) looks closely at your cancer.
Can stage 1 colon cancer come back? Most people with stage 1 colon cancer do well after treatment. In fact, about 90% of people treated for stage 1 colon cancer live at least 5 years after the cancer is found.