This Sunday, March 31, is World Colon Cancer Day, one of the most prevalent cancers in our society. Dr. Lorenzo Viso, specialist in Coloproctology and member of Top Doctors, answers our questions and explains the importance of early diagnosis and prevention tests.
How can colon cancer be diagnosed?
Colorectal cancer is usually diagnosed with a colonoscopy that shows the presence of a lump in the lumen of the colon or rectum, which must be confirmed with a positive biopsy for malignancy.
Why are preventive tests important and who are they aimed at?
They are very important, since the prognosis of the disease is influenced by the time of evolution of the neoplasia, i.e., the longer the time of evolution, the greater the extension of the pathology and the worse the prognosis.
Therefore, a population screening colonoscopy in people over 40 years of age would be ideal. The fecal occult blood test which, at present, diagnoses the presence of human hemoglobin in the fecal contents, has been of great help in this sense because it filters the people who should undergo this colonoscopy.
What situations or results will make us suspect a possible colon cancer?
In addition to the fecal occult blood test, there are a series of situations, symptoms or data that are suspicious and make it necessary to rule out colorectal cancer:
- Iron deficiency anemia (lack of iron) without evidence of bleeding through another organ.
- Unexplained change in stool habit or rhythm, such as increased number of bowel movements, abnormal tendency to constipation, presence of mucus in the stool, expulsion of gas with mucus and even blood in small amounts.
- Abdominal pain, cramping type.
- Presence of blood in the stool, especially if the blood is mixed with the stool. The specialist will be the one to judge whether the type of rectorrhagia is suspicious or if it is simply hemorrhoids. However, at the slightest doubt, a colonoscopy will be performed.
- Presence of an elevated CEA (Carcino-Embryonic Antigen) in a blood test. This tumor marker is associated with colorectal cancer but, in most affected patients, it does not increase.
- Toxic syndrome: lack of appetite, feeling of tiredness and/or weight loss.
Are there groups more prone to suffer from colon cancer?
The proportion of men and women with colorectal cancer is similar. Age, although it is more frequent after the fifth decade of life, is a factor that is weakening at present, since cases are being diagnosed at very early ages.
Between 5 and 10% of colon cancer cases can be considered hereditary. This is called HNPCC (Hereditary Non-Polyposis Colorectal Cancer) or Lynch Syndrome. Families that should be studied as possible carriers of this syndrome are those in which the following situations are present:
- They have three or more family members who have had colon cancer or other associated tumors (endometrial, ovarian, ureter, renal pelvis or small bowel).
- One of those affected is a first-degree relative of others in the family with any of the above-mentioned tumors.
- It affects at least two generations.
- One of the persons must be at least under 50 years of age when the diagnosis of the malignant tumor was made.
- The cancer must be confirmed with anatomic pathology studies.
- Other diseases, such as familial adenomatous polyposis, must be ruled out.
Does lifestyle influence colon cancer?
There is no scientific evidence to confirm that lifestyle is related to a greater probability of developing colorectal cancer. However, it is true that developed countries have a higher prevalence of the disease.
What will the prognosis of colon cancer be like depending on when it is diagnosed?
The prognosis of the disease is linked to its extension. Several factors are important: the penetration of the tumor into the intestinal wall, the presence of affected regional lymph nodes in the specimen removed during surgery or the presence of distant metastases. Also other more specific aspects that will be confirmed by the anatomopathologist, such as the biology of the tumor (there are some with more aggressive cellularity than others), the degree of cellular differentiation, lymphatic vascular permeation of the tumor, perineural invasion, the patient’s response to the cancer, etc.