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.
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.
Not all polyps pose a higher risk for colorectal cancer. But some colon cancers may start as polyps. So, the more polyps you have, the higher your cancer risk. Someone with just one or two small polyps is generally at lower risk of having or developing colon cancer than someone with three to nine, or more.
While the majority of colon cancers start as polyps, only 5-10% of all polyps will become cancerous.
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.
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.
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.
Most polyps grow slowly and take from between 10 and 15 years to become 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.
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.
Polyp Growth Rates
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).
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.
In multivariable analysis, the presence of 5 or more polyps at index colonoscopy was found to be associated with the risk of metachronous HR-CRN (OR, 2.575, p = 0.049) after adjusting for risk factors, such as obesity, diabetes, and smoking.
Most colon polyps can be removed during a colonoscopy. That's one reason doctors like colonoscopies so much.
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.
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!
Regular screening, beginning at age 45, is the key to preventing colorectal cancer and finding it early.
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].
Most colorectal cancers start as colon polyps, abnormal growths in the wall of the colon. Some polyps can develop into cancer if left untreated for a long time (usually at least 10 years). Screening is crucial for cancer detection because most colorectal cancers don't cause symptoms in the early stages.
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.
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.
Polyps are benign, meaning that they're not cancer and they won't spread, but over time certain types can develop into cancer. One of these types is called adenomatous polyps. These are known as pre-cancerous polyps. Polyps bigger than 1 centimeter have a greater cancer risk than polyps under 1 centimeter.