Do colon polyps always turn into cancer if not removed?

Not all colon polyps will turn into cancer if not removed. An adenoma is a precancerous lesion. It has a risk to progress to invasive cancer. For a standard adenoma, a so-called low-grade dysplasia, the risk of progression is actually low, probably less than 10 percent. When there's more advanced features in an adenoma, but it hasn't quite made it to cancer, it is called high-grade dysplasia. So, the pathologist looks at the cells, and if the cells are concerning with these features, they call it high grade.

On a spectrum of normal mucosa up to cancer, a low-grade adenoma has a slightly higher risk to progress to invasive cancer, which just means basically that if it isn't removed, it's more likely to progress to cancer. After it is removed, that person has a higher risk of developing polyps including polyps with high-grade dysplasia in the future, so doctors need to keep a closer eye on that person.

It is hard to know if all colon polyps turn into cancer because polyps are rarely left in the colon long enough to “wait and see.” However, it does take many years for a polyp to develop into cancer. Research demonstrates that most cancers arise through a series of abnormalities. For instance, most polyps start as benign tumors (tubular adenoma), then develop low grade dysplasia (abnormal cell growth) which changes to high grade dysplasia, and then finally into cancer. These changes are usually a result of mutations in the DNA of the polyp’s cells. Each phase may take months or years to progress; however, the best way to prevent colon cancer is through regular screening via colonoscopy with removal of any polyps or abnormal growths.

Polyps are small, painless tissue growths that can form in the colon for reasons that are not clear. Most polyps are benign and in their present form are not a threat to health. But some colon polyps can turn cancerous, or malignant, and malignant tumors in the colon are life threatening.

Keep in mind, however, that most polyps do not develop into colon cancer. Furthermore, polyps that have been detected in the colon can be removed, eliminating the possibility that a particular polyp will turn cancerous.

Polyps tend to grow slowly over time and do not always result in cancer. That being said, however, the chance of cancer formation increases as the polyp increases in size. This is why we remove polyps at the time of colonoscopy.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.