Colon cancer: what is it and how to prevent it

What is colon cancer?

It is a malignant tumor that can affect any section of the colon including the rectum. It originates in an uncontrolled proliferation of the cells of the mucosa of the colon, which give rise to a polyp. With the passage of time this polyp can invade the wall of the colon, the nearby ganglia and distant organs, such as the liver or the lung, giving rise to metastasis.

The importance of colon cancer lies in its frequency: it is estimated that this year in Spain about 30,000 new cases will be diagnosed, which means that one out of every 20 people will develop colon cancer throughout their lives.

Can it be prevented?

The positive thing about colon cancer is that you can make an early diagnosis and prevention. In primary prevention, we would treat cancer risk factors such as obesity, smoking, alcohol, sedentary lifestyle, high-fat diet, red meat, etc.

However, where we have gained the most, where mortality from colonic cancer has been shown to decrease is in secondary prevention, which consists in the detection of premalignant lesions and in their extirpation through colonoscopy, a tremendously reliable technique.

Another option would be the detection of occult blood in stool, because we know that polyps lose blood. It is a less reliable technique, less sensitive than colonoscopy, but when it tests positive, we do the colonoscopy.

What is the recommendation to follow?

The colon cancer prevention strategy may vary depending on the health policies and the risk of the patient, but ultimately a patient with high risk, who has a family history of colon cancer, who have already had polyps removed. Do a colonoscopy every five years starting at age 50 and sometimes even before.

The individual with medium risk, who is more than 50 years old without these antecedents, is advisable to have an annual or biannual fecal occult blood and, when positive, a colonoscopy in order to detect and eradicate or remove the lesions. premalignants, preventing it from progressing to cancer and thereby avoiding mortality.

What is colonoscopy?

When I speak of colonoscopy I refer to the optical colonoscopy or videocolonoscopy, not to the virtual one, because this one does not have possibilities of making biopsies or of extirpating lesions. As its name suggests, video colonoscopy is a flexible device that is inserted through the anus, which has a camera at its distal end and allows visualization of the entire mucosa of the colon from the anus to the cecum.

If we see a tumor, we can biopsy it, if we see a polyp, we can remove it, we can recover it for analysis, what is important. As we see, it is an invasive exploration, therefore annoying and it must be done correctly with sedation or anesthesia. Another condition is that the colon has to be clean, for which the patient will have to take a preparation.

It has some risk, such as post-polypectomy bleeding, which can be controlled by endoscopy, or perforation that may require an operation, but the final balance is positive. With colonoscopy we have managed to reduce mortality from colon cancer.