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.
Ninety percent of cases occur after age 50, with males somewhat more likely to develop polyps than females; therefore, colon cancer screening is usually recommended starting at age 50 for both sexes. It takes approximately 10 years for a small polyp to develop into cancer.
Colon cancer, or cancer that begins in the lower part of the digestive tract, usually forms from a collection of benign (noncancerous) cells called an adenomatous polyp. Most of these polyps will not become malignant (cancerous), but some can slowly turn into cancer over the course of about 10-15 years.
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.
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.
People who have had certain types of polyps removed during a colonoscopy. Most of these people will need to get a colonoscopy again after 3 years, but some people might need to get one earlier (or later) than 3 years, depending on the type, size, and number of polyps.
People who have precancerous polyps completely removed should have a colonoscopy every 3-5 years, depending on the size and number of polyps found. If there are 1-2 polyps <1 cm in size (~1/2 inch), then another colonoscopy in 5 years is appropriate.
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.
Most polyps grow slowly and take from between 10 and 15 years to become cancerous. Due to this general time frame, most screenings are scheduled every 10 years which gives Colorectal Surgical Associates time to remove any polyps before they become cancerous.
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).
These organs are both part of the digestive system. This is where food is broken down to make energy and where the body gets rid of solid waste (poop or stool). On the picture above you can see where the colon and rectum are inside the body. In most cases, colon and rectal cancers grow slowly over many years.
Most colorectal cancers start as a growth on the inner lining of the colon or rectum. These growths are called polyps. Some types of polyps can change into cancer over time (usually many years), but not all polyps become cancer. The chance of a polyp turning into cancer depends on the type of polyp it is.
Age. The risk of colorectal cancer increases as people get older. Colorectal cancer can occur in young adults and teenagers, but the majority of colorectal cancers occur in people older than 50. For colon cancer, the average age at the time of diagnosis for men is 68 and for women is 72.
What Are the Main Causes? Several factors contribute to the development of colon polyps, including genetics, personal history, diet, obesity, smoking, and certain medications. Genetics. Your genes play a role in whether you will develop colon polyps.
Once a colorectal polyp is completely removed, it rarely comes back. However, at least 30% of patients will develop new polyps after removal. For this reason, your physician will advise follow-up testing to look for new polyps. This is usually done 3 to 5 years after polyp removal.
Age. Most people with colon polyps are 50 or older. Having inflammatory intestinal conditions. Ulcerative colitis or Crohn's disease of the colon increase your overall risk of colon cancer, although the polyps themselves are not a significant threat.
While the majority of colon cancers start as polyps, only 5-10% of all polyps will become cancerous.
Your doctor can't usually tell, simply by looking at a polyp during a colonoscopy, if it's cancerous. But if a polyp is found during your colonoscopy, your doctor will remove it and send it to a lab for a biopsy to check for cancerous or precancerous cells.
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.
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.
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.
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.
There are many types of colon cancer screenings, but colonoscopy is the most effective method because it is the only test that can detect and remove colon cancer in the same procedure. Under current guidelines, patients who have a colonoscopy with normal findings should get screened again in ten years.