From good polyps to bad polyps: colon cancer
“There are polyps that already contain cancer cells; others are benign, but with great potential for malignancy; some have a low probability of developing into cancer; and many, simply, do not generate the dreaded neoplasia (adenomas)”, explains the specialist in the digestive system.
The whole surface that covers the inside of the digestive system, including the colon, is called mucosa. A polyp is nothing more than a tiny area of this mucosa where an amorphous mass of cellular tissue develops.
“This kind of protrusion can show several forms, but two very common types stand out: dome-shaped (sessile polyp) or like a sphere connected to the mucosa by a stalk (pediculated polyp)”, describes the also president of the Spanish Society of Gastroenterology.
Polyps in the colon are very common, being able to diagnose up to 30 or 50% of cases in adults. Studies estimate that it can take at least ten years from the time a polyp appears until it turns into cancer.
“The good news – he underlines – is that they can be removed during the process of a colonoscopy test; intervention that allows, at the same time, an anatomopathological analysis to observe its potential malignancy. This way we will avoid the development of polyp tumors, eliminating them from our body”.
“It must be remembered that the colon or large intestine is the last part of the whole intestine, where the process of digestion.
The last remnants of ingested food arrive in the colon, with very few nutrients. In this intestinal area, the remaining water and nutrients generated after the relevant fermentation carried out by the microbiotaresidents who enter this area with their own identity data.
With all this leftover organic material, faeces are formed, waste from the remains of undigested food and other products or fluids that contain, for example, bile from the liver”.
Dr. Enrique de Madaria Pascual
The polyp as an advance of cancer
At global level, colon cancer appears in the fourth position of malignant tumors that afflict the population; breast, lung and prostate cancer are in the top three positions.
In 2023, 279,260 new cases of cancer will be registered in Spain, compared to 280,100 the previous year, according to the report on cancer figures prepared by the Spanish Society of Medical Oncology (SEOM).
The most frequently diagnosed cancers in our country will be those of the colon and rectum (42,721), breast (35,001), lung (31,282), prostate (29,002) and urinary bladder (21,694). Tumors such as the stomach “only” will affect 6,932 people.
In men, the prostate, colon and rectum, lung and urinary bladder will be the majority; in women, breast, colon and rectum.
In the world and with data from the year 2020, the cancers that caused the greatest number of deaths were lung (18.2% of the total), colorectal (9.5%), liver (8.4%) , stomach (7.8%) and breast (6.9%).
Colon cancer usually announces its presence with obvious symptoms
“We will feel and observe changes in the way we defecate, such as frequent onset constipation or diarrhoea, bleeding in stools, abdominal pain and sometimes intestinal obstruction,” the gastroenterologist points out.
“If the inside of the colon gets blocked, we will notice swelling of the abdomen, inability to do bowel movements, abdominal pain and vomiting when the contents of the colon get clogged,” he specifies.
“Of course, most people who suffer from diarrhea, constipation, abdominal pain or bleeding usually suffer from other diseases or less important problems, but you need to be alert to the possibility of colon cancer.”
In fact, it is necessary to take into account the risk factors that underpin this tumor.
“Obesity, diabetes, frequent consumption of red or processed meat, smoking, alcohol and some genetic mutations, the origin of family diseases that predispose more often than usual to suffering from these cancerous tumors,” points out Dr. . Enrique de Madària.
On the contrary, daily physical activity and a diet rich in fruit and vegetables, probably fiber, garlic, magnesium and dairy products are the best allies against colon cancer”, he advises.
Even so, some diseases of the colon can also predispose to the appearance of tumors.
The “polyps” plan that prevents colon cancer
Colon cancer is common mainly due to polyps in the large intestine, a mass of tissue that precedes it and can be removed: today there are programs for the prevention and early diagnosis of colon cancer.
Prevention of this type of cancer should begin around the age of 45 or 50, in both men and women, unless the patient has a family history of genetic diseases that predispose to this tumor.
The focus is on two strategies to prevent colon cancer in the population.
“One possibility would be to do a fecal occult blood test, usually once a year. The other would consist of doing a colonoscopy and repeating the intervention every ten years”, informs Dr. from Madaria.
“Large polyps and colon cancer tend to bleed so minimally that blood in the stool is not visible to the naked eye. But a test does detect this small amount of blood in the stool”, he emphasizes.
“These tests are done periodically and, if the result of any of them is positive, the inside of the large intestine should be visualized with a colonoscopic examination to rule out polyps or colon cancer,” he teaches.
Most people with a positive test will not have cancer, but it is common to find polyps in the colon.
“On some occasions, the positive test in excrement will have its origin in hemorrhoids or fissures in the anal area, without there being either polyps or tumors. Even so, the benefit of the test to detect and prevent colon cancer is enormous”, he says bluntly.
What does a colonoscopy consist of?
Colonoscopy examines the entire colon and rectum. The device integrates a mini television camera attached to the end of a probe or tube connected to the colonoscope.
The probe is gently inserted through the anus.
The device will be able to introduce air into the colon for a better examination of the mucosa and, in addition, it will be able to suck out liquids and fecal remains to clear obstacles to visualization.
If a polyp is found in this part of the intestine, it can also be removed after embracing and tying it with a wire loop (polypectomy).
Sometimes, when cutting the tumor mass, electric current is applied to cauterize the resulting wound so that it cannot emanate blood.
The sectioned polyp is recovered to be analyzed under a microscope and checked for malignancy
As a general rule, colonoscopy reduces the chances of colon cancer returning in 90% of cases.
Dr. Enrique de Madaria Pascual, doctor specializing in the digestive system and president of the Spanish Society of Gastroenterology.