Preventing Colorectal Cancer

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The purpose of primary prevention is to avert the appearance of colorectal cancer by changing dietary habits and following a healthy lifestyle.

While the impact of adopting these measures is unclear, the main recommendations in this regard are:


Moderate the consumption of red meats, processed meats and very well-done meats or which have been in direct contact with flames.

Bottle with correct calcium drink

Follow a low-fat diet rich in fibre, fruits, vegetables, milk and dairy products. 


Consume an adequate intake of folic acid, calcium and vitamin D.


Woman doing exercise

Exercise and avoid overweight and obesity

Cigarette crossed out on a "no smoking" poster

Avoid tobacco use and moderate alcohol consumption.

Three Aspirins

Even though taking acetylsalicylic acid and non-steroidal anti-inflammatory agents reduces the risk of developing colorectal cancer, the adverse cardiovascular, gastrointestinal and renal effects means the systematic use of these drugs to prevent colorectal cancer is not recommended.

Secondary prevention or screening aims to detect the cancer or polyps in an early stage, before the symptoms start to appear (blood in stools, constipation, diarrhoea, anaemia, etc.). The purpose of screening tests is to prevent the appearance of colorectal cancer (by removing the precursory lesions or polyps before they degenerate into cancer) and to reduce the death rate associated with it (as the earlier the colorectal cancer is detected, then the greater the chances of being cured).

Screening strategies vary in function of each person’s risk of developing colorectal cancer:

A man and a woman over 50 years of age

Population with a medium level of risk are individuals aged ≥ 50 and who present no other risk factors associated with colorectal cancer (neither any personal medical history of this cancer or polyps, nor any family history of colorectal cancer). Members of this group (men and women aged 50–69 years) are advised to participate, every 2 years, in the colorectal cancer population screening programme which works by detecting faecal occult blood (FOB). The FOB test detects invisible traces of blood in stools, which can indicate the presence of a polyp or colorectal cancer; if blood is detected, then the patient should undergo a colonoscopy.

Family tree

A family history including relatives who have suffered colorectal cancer increases an individual’s risk of developing the disease. In such cases the most appropriate screening test  is a colonoscopy, while the age to initiate screening and the frequency of tests depend on the number of effected relatives, their ages at diagnosis and the degree of kinship.

Family and family tree indicating hereditary factors

People with a family history of hereditary colorectal cancers (e.g., Lynch syndrome or familial adenomatous polyposis) have a high risk of developing colorectal cancer. Screening through colonoscopies performed in special units is recommended for these cases.

Tertiary prevention or surveillance in patients who have already suffered polyps or colorectal cancer aims to avert the consequences associated with the development of these lesions. This group of patients should therefore receive colonoscopic surveillance to detect if the cancer reappears or any new polyps as early as possible.

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Substantiated information by:

Antonio Maria Lacy Fortuny
Estela Pineda Losada
Francesc Balaguer Prunes
Mª Rosa Costa Quintàs

Published: 20 February 2018
Updated: 20 February 2018

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