You should be screened regularly for polyps if: You're age 50 or older. You have risk factors, such as a family history of colon cancer. Some high-risk individuals should begin regular screening much earlier than age 50.
As a general rule, the larger the adenoma, the more likely it is to eventually become a cancer. As a result, large polyps (larger than 5 millimeters, approximately 3/8 inch) are usually removed completely to prevent cancer and for microscopic examination to guide follow-up testing.
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.
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).
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.
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.
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.
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.
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. So as long as patients are screened, it is unlikely they will develop cancerous polyps.
They can occur anywhere in the large intestine or rectum, but are more commonly found in the left colon, sigmoid colon, or rectum.
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.
Colonoscopy, the most sensitive test for colorectal polyps and cancer. If polyps are found, your doctor may remove them immediately or take tissue samples (biopsies) for analysis.
A polyp is the result of genetic changes in the cells of the colon lining that affect the normal cell life cycle. Many factors can increase the risk or rate of these changes. Factors are related to your diet, lifestyle, older age, gender and genetics or hereditary issues.
Not all polyps are precancerous or cancerous. Sometimes the nature of a polyp can be distinguished based on how it looks during a colonoscopy. But only removal for examination under a microscope by a pathologist can accurately determine if a polyp is precancerous.
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.
Bowel polyps do not usually cause any symptoms, so most people with polyps will not know they have them. They're often picked up during screening for bowel cancer. But some larger polyps can cause: a small amount of slime (mucus) or blood in your poo (rectal bleeding)
Pain. Persistent pain in the abdomen usually occurs with a large polyp as it begins to cause an obstruction in the colon.
Adenomas: Many colon polyps are the precancerous type, called adenomas. It can take seven to 10 or more years for an adenoma to evolve into cancer—if it ever does. Overall, only 5% of adenomas progress to cancer, but your individual risk is hard to predict.
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).
Common Symptoms of Colon Polyps
Changes in Bowel Movements – Sometimes colon polyps can lead to constipation or diarrhea that persists for longer than a week, as well as general changes in bowel habits.
These polyps have the potential to become cancer if given enough time to grow. Most of these colon polyps are called adenomas. Serrated polyps may also become cancerous, depending on their size and location in the colon. In general, the larger a polyp, the greater the risk of cancer, especially with neoplastic polyps.
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).