While the majority of colon cancers start as polyps, only 5-10% of all polyps will become cancerous.
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.
Q: How long does it take for cancer to form on a colon polyp? A: Time is on your side when it comes to colorectal cancer forming in a polyp. The process is estimated to take 10 years — a period that leaves ample opportunity for early discovery and treatment.
Number: The more pre-cancerous polyps someone has, the higher their risk will be. So, someone with 1 or 2 small polyps is at less risk than someone with 3-9.
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 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!
If your doctor finds precancerous polyps, there is no need for any additional treatment as long as they remove the entire polyp. Removing the tissue stops the development of cancer.
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.
Risk factors for metachronous high-risk colorectal neoplasms
Specifically, patients with 5 or more polyps at index colonoscopy had a significantly higher risk of metachronous HR-CRN (OR, 3.552; 95% CI, 1.522–8.290; p = 0.003).
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.
Patients aged 50 years or older were more likely to have sessile polyps (p=0.023) and polyps located in the proximal colon (p=0.009). There were no significant differences between groups in histopathology or presence of dysplasia.
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 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.
Foods to limit
Research suggests that eating less of the following foods may have health benefits and may lower your chances of developing polyps: fatty foods, such as fried foods. red meat, such as beef and pork. processed meat, such as bacon, sausage, hot dogs, and lunch meats.
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.
Villous Adenoma (Tubulovillous Adenoma)
Approximately 15 percent of polyps detected in colon cancer screening are villous or tubulovillous adenomas. This type of polyp carries a high risk of turning cancerous.
Patients with either advanced adenoma or large serrated polyp should undergo repeat lower endoscopy within 3 years of diagnosis to reduce incidence of and mortality associated with colorectal cancer, according to research results published in Gastroenterology.
The presence of PTSD has a marked impact on colonoscopy rates in Australian veterans. The increased polypectomy rate independent of increased colonoscopy rate suggests that PTSD is a risk factor for colonic polyp formation.
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.
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). Evidence from the heyday of barium enema examinations indicates that most polyps do not grow or grow very slowly (18).
Factors are related to your diet, lifestyle, older age, gender and genetics or hereditary issues. Important lifestyle factors predisposing to colorectal polyps and cancer (making you more liable to get these conditions) include: Smoking. Excess alcohol ingestion (drinking too much alcohol).
If a polyp is removed completely, it is unusual for it to return in the same place. The same factors that caused it to grow in the first place, however, could cause polyp growth at another location in the colon or rectum. New polyps will develop in at least 30 percent of people who have previously had polyps.
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.
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. Colon cancer can be fatal when found in its later stages.