What is a risk factor?
A risk factor is something that increases a person's likelihood of developing a disease. However, although they can influence, it is not known for sure how they cause the disease.
What are the risk factors for cancer?
Cancer, like any other disease, has risk factors that make people more susceptible to developing it. Risk factors for cancer can be divided into:
- Controllable:
- Environmental Exposure
- lifestyles (e.g. diet and physical activity)
- infections with certain viruses, bacteria or parasites
- Non-controllable:
- age
- Genetic predisposition
- ethnicity
Is environmental exposure a risk factor?
yes. Every day we are exposed to harmful and toxic agents. Long-term exposure to many of these agents, called carcinogens, can increase the risk of cancer.
What are the most common types of carcinogens?
Carcinogens can be divided into two types:
- Chemicals – all the air pollutants to which we are exposed on a daily basis, such as gases (from cars and industrial chimneys) and synthetic products (glues, paints, among others), but also some chemicals present in processed foods
- physical – ultraviolet radiation, transmitted by the sun, X-radiation that is transmitted by medical radiology equipment and radioactive material in place, for example, in uranium mines
Can lifestyle be a risk factor?
yes. Healthy lifestyles have been shown to decrease the likelihood of developing cancer. Thus, having incorrect lifestyles, such as poor eating habits, smoking, drinking alcohol excessively and being sedentary, are considered high risk factors for cancer.
Is diet a risk factor?
yes. A diet low in fruits and vegetables, little varied and abundant in fats and sugars is a major risk factor for the development of several diseases, including stomach and bowel cancer. Obesity is associated with cancer due to the disordered and uncontrolled multiplication of altered cells.
A healthy diet is essential for maintaining a good state of health and quality of life.
What types of cancer does smoking cause?
Tobacco use is associated with an increased risk of cancer of the oral cavity, pharynx, larynx, trachea, oesophagus, pancreas, lung and bladder.
What types of cancer does alcoholism cause?
Excessive and prolonged consumption of alcoholic beverages increases the risk of head and neck, oesophagus, liver, breast and colon cancer.
Do sedentary people have a higher risk of cancer?
yes. Sedentary people have a higher risk of developing breast, colon, esophageal and uterine cancer. The practice of physical exercise in a regular and moderate way is a preventive factor for several diseases.
Which infections are risk factors for cancer?
Some studies in the field of oncology show that infections with certain viruses, bacteria or parasites increase the risk of certain types of cancer. Examples are:
- Epstein-Barr virus – this virus causes mononucleosis and is associated with some types of lymphoma and head and neck cancer
- hepatitis B virus and hepatitis C – chronic infections with these viruses cause hepatocarcinoma (liver cancer)
- Human Immunodeficiency Virus (HIV) – HIV infection compromises the immune system, increasing the risk for several types of cancers, namely lymphomas, Kaposi's sarcoma, among others
- human papillomavirus (HPV) – Some types of this virus are classified as high risk and are responsible for the development of almost all cervical cancers. This type of virus is also implicated in cancers of the oropharynx, vagina, penis and anal canal
- helicobacter pylori – infection with this bacterium is associated with a type of gastric cancer and MALT lymphoma
- Schistosoma hematobiuM – a parasite present in Africa that is associated with bladder cancer
Is aging a risk factor?
yes. Age is the main risk factor for many types of cancer, as the aging of cells leads to the development of cancer.
About a quarter of new cancer cases are diagnosed in people aged between 65 and 74. Therefore, enhanced surveillance is recommended from the age of 50.
What does it mean to have a genetic predisposition?
Hereditary cancer syndromes are a high risk factor, accounting for about 5 to 10% of all cancers.
Individuals who have close family members with cancer, especially at a young age, may have a higher risk of developing the disease. For example, a woman whose mother or sister has had breast cancer is twice as likely to develop breast cancer as another woman who does not have the same family history.
Are there tests to diagnose genetic predisposition?
yes. Genetic tests to search for hereditary cancer mutations can be ordered by the attending physician, in case of suspicion of hereditary syndrome, and referred for oncogenetics consultation.
How can cancer prevention be done?
By avoiding risk factors such as smoking, poor eating habits, prolonged exposure to the sun and acquiring healthy lifestyle habits (such as regular exercise, a balanced diet, drinking water, etc.) you can greatly reduce the risk of developing certain types of cancer. Unfortunately, not all cancers can be prevented.
However, the earlier it is diagnosed, the more likely it is to be cured. For this reason, it is so important to monitor changes in your body and perform regular self-examination of the breast, testicles and skin. Your doctor may also advise regular screening tests, such as:
- mammography
- fecal occult blood test
- gynecological examination with cytology (Pap smear)
- digital rectal examination
- Blood tests
- among others
To determine which tests are most appropriate for each person, the doctor will take into account age, family history of cancer, ethnicity and other possible risk factors.
Source: Portuguese Society of Oncology