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Cancer: causes and prevention

Each year, more than 10 million new cases of cancer are reported in the world. Cancer is one of the main causes of death in Western countries, where it is responsible for approximately one in four deaths. Cancer (malignant tumors) is characterized by the spreading of abnormal cells. These cells invade neighboring tissues and, in the absence of diagnosis and early treatment, can spread throughout the entire body. Cancer can affect any body tissue. However, cells that reproduce infrequently, such as muscle fibers and neurons, are very rarely affected by the disease. Some types of cancer, like breast or colon cancer, are encouraged by hereditary predispositions. However, it is estimated that 90% of cancer cases are due to external factors, of which 80% could be linked to an individual’s lifestyle. Tobacco, poor dietary habits, viruses, chemical substances, and radiation are among the main causes of cancer.


Between 80% and 90% of lung cancer cases are caused by tobacco, which releases toxic substances during consumption. Tobacco is also responsible for mouth and larynx cancer and it promotes numerous other cancers (bladder, esophagus, etc.). The carcinogenic effect of tobacco is multiplied when it is combined with alcohol.

Poor dietary habits

There are correlations between certain dietary habits and certain cancers, particularly the overconsumption of fat and a lack of fiber (colon cancer) or vitamins. Alcohol is a risk factor for cancer of the liver, mouth, pharynx, and esophagus.

Chemical substances

Several chemical substances have been recognized as carcinogenic, meaning susceptible to causing cancer: tar, asbestos, heavy metals, paint solvents, pesticides, etc.


Certain viruses can promote genetic modifications of the cells that they infect. Also, the hepatitis B virus can cause liver cancer. Certain types of papillomavirus, which are sexually transmitted, can cause cervical cancer. In addition, a virus leads to the weakening of the immune system, which can prevent the body from efficiently fighting the appearance of abnormal cells.


An individual can be exposed to radiation that is natural (from the sun) or artificial (radiological exams, nuclear tests, tanning lamps, etc.). Their carcinogenic effects are observed above a certain dose that can vary depending on the individual.

Cancer prevention

Some cancers are caused by factors that are beyond our control, but for the majority of them, their occurrence can be prevented by modifying our lifestyle habits. Here are a few precautions to take to lower the risks of developing cancer, or to quickly stop its progression.

Pay attention to warning signs

Cancer does not always manifest itself with specific signs, but certain perpetuated or intensified symptoms require particular attention, specifically if you are an at-risk individual (smoker, alcoholic, person with a family history of cancer). Consult a doctor if you experience any of the following symptoms:

  • Abnormal, lasting, and growing fatigue
  • Loss of appetite or significant weight loss
  • Resistant fever
  • Specific points of pain that may intensify
  • Abnormal bleeding
  • Repeated infections
  • Nodule or hardening, painful or not, of the skin, muscle, breast, or testicle
  • Lesion that does not heal and spreads
  • Wart or beauty mark that changes: thickening, color change, bleeding

Have regular screening tests

Early cancer screenings thanks to different exams allow for more rapid and less intensive treatment, which noticeably increases the chances of recovery. You should regularly have these exams, if possible, specifically if you are an at-risk individual: mammograms for breast cancer, cervical smears for cervical cancer, a colonoscopy for cancer of the colon and rectum, a rectal exam for prostate cancer, self-checks for skin cancer, testicular cancer, breast cancer, etc.

Adopt a healthy and balanced diet

A varied and balanced diet is the key to good health and preventing cancer. It is important to limit your consumption of food that is rich in salt, in calories, or in fatty animal materials, like red meat, deli meat, fast foods, or soft drinks. The consumption of 5 to 10 servings of fruit and vegetables per day is also recommended. Eat foods that are rich in fiber, vitamins, and antioxidants like whole grains, nuts, vegetable oils, red fruit, green vegetables, tomatoes, cauliflower, and fish.

Maintain a healthy weight

Being overweight is an aggravating factor for some cancers, like lung cancer, uterine cancer, and colon cancer. To maintain a healthy weight, adopt a balanced diet and exercise regularly.

Consume alcohol in moderation

The excessive consumption of alcohol promotes damage that can cause cancer of the liver, esophagus, mouth, and throat. The risk increases if you combine alcohol consumption with cigarettes.

Don’t smoke

Smoking is the number one cause of lung cancer, but it can also cause other cancers (mouth, larynx, liver, esophagus, etc.). Second-hand smoke is also a non-negligible risk factor.

Exercise regularly

Physical activity decreases the risks of cancer by stimulating the immune system. You should regularly do endurance, flexibility, and muscle strengthening exercises.

Protect yourself against sexually transmitted infections

Short of having a stable relationship with your partner, use a condom during every sexual encounter.Certain sexually transmitted viruses, such as human papillomavirus, can lead to cancer (cervical cancer).

Protect your skin from the sun

Intensive exposure to rays from the sun can lead to skin cancer, even several years after exposure. Protect yourself from the sun and avoid using tanning beds or lamps.

Take care of and prevent diseases that may lead to cancer

Certain diseases, like hepatitis B, can lead to cancer. It is important to treat them or to protect yourself against them through vaccination.

Handle hazardous products carefully

Certain substances or chemical products, like asbestos, pesticides, or paint, contain hazardous elements that may cause cancer. To protect yourself, avoid them, or use them with caution: work in a well-ventilated place, wear protective clothing, a mask, etc.

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