Can we prevent colon cancer?
We know that 85% of malignant tumors of the colon originate from an adenomatous polyp that progresses to cancer throughout an evolutionary cycle lasting 3-10 years. If we perform a colonoscopy and remove the polyp, we cut the evolutionary cycle, its natural history.
Do all polyps turn into cancer?
Not fortunately. Only 10% will complete the Polyp → Cancer cycle and this depends on three factors:
- Size of the adenomatous polyp
- Histological type
- Degree of displasia
A tubulovillous or villous polyp with a high degree of dysplasia will have more malignant potential than a tubular adenoma with low grade dysplasia.
What risk do I have of having an adenomatous polyp?
The prevalence of having an adenomatous polyp depends on four factors:
- Inherent risk of colon cancer in the population
- Family history of colorectal cancer
What symptoms produce the polyps?
Most do not produce symptoms. When the size of the polyp is 2-3 cm, it can produce small red blood emissions or test positive for fecal occult blood.
Does age influence?
The prevalence of adenomatous polyps is higher in older people, particularly those older than 60 years. In fact, age is the single most important independent determinant in the prevalence of adenomas.
15% of colon tumors that do not originate from an adenomatous polyp, what origin do they have?
Rarely, colon cancer can appear “de novo” in a flat and non-adenomatous epithelium and it can be assumed that even these lesions may originate in pre-existing flat adenomas.
If I do not have symptoms, should I have a colonoscopy?
Yes, for what we have explained above. The prevalence of colon cancer increases with age. It is appropriate to perform colonoscopy between 50 and 60 years of age as a screening.
If I have a family history, at what age should I have a colonoscopy?
It is recommended 10 years before diagnosis in the first degree relative, but this is variable.
Colonoscopy is an invasive procedure; are there alternative non-invasive methods?
The fecal occult blood test, but its sensitivity and specificity is less than 40%. The sensitivity and specificity of Colonoscopy reaches 90%.
What is the prognosis of colon cancer?
If we detect it in an early phase by means of colonoscopy the possibilities of cure are around 90%.
Dr. Manuel Morales Gordo, specialist in Digestive and Endoscopic Devices / Policlínica Comarcal del Vendrell