Smoking - Lung Cancer Facts

Smoking and lung cancer (primary carcinoma of the lung) are both well documented but one of the most critical and less often touted facts the disease is that smoking is THE major cause.

Tobacco smoke also causes chronic lung disease and contributes to bladder, pancreas, and kidney cancers.


Lung cancer normally takes many years to develop. Incidence tends to peaks between the ages of 55 and 65 years. The changes in the lung however can begin almost as soon as a person is exposed to carcinogenic chemicals.

Soon after exposure begins, a few abnormal cells may appear in the lining of the bronchi (the main breathing tubes).

Gradually, as you continue your exposure to these substances, more abnormal cells appear. Some will become cancerous and tumour forming.

If you stop smoking however, the risk of lung cancer decreases. Year on year, abnormal cells are replaced by normal cells. After ten years, the risk drops to a level that is one-third to one-half of the risk for people who continue to smoke.

Quitting smoking greatly reduces the risk of developing other smoking-related diseases, such as heart disease, stroke, emphysema and chronic bronchitis but there are many more benefits to quitting smoking.

Key Facts

  • Primary carcinoma of the lung is the leading cause of cancer deaths in both men and women.
  • It accounts for approximately 32% of cancer deaths in men and 25% in women.
  • Current or former cigarette smokers make up approximately 90% of patients with the disease.
  • Men who smoke one pack a day increase their risk 10 times compared with non-smokers.
  • Men who smoke two packs a day increase their risk more than 25 times compared with non-smokers.
  • The more you smoke and the longer you smoke, the greater your risk.
  • Of the 180,000 people diagnosed in the United States alone each year, 86% will die within 5 years of diagnosis.
  • Chemicals and compounds in tobacco smoke make it cancerous and the cause of other harmful health effects of smoking.

Different Types

There are two major types of lung cancer:

  • Non-small cell lung cancer - consists of 3 types:
    • Squamous cell carcinoma
    • Ademocarcinoma and
    • Large cell carcinoma
  • Small cell lung cancer also called oat cell. It usually spreads to different parts of the body more quickly than non-small cell and accounts for about 20% of all incidents.

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