Question:

How long does it take lung cancer to develop from smoking? How common would it be to develop lung cancer after 5 to 10 years of smoking and only smoking 10 cigarettes a day? I have heard it take many years for lung cancer to develop but am not sure what is meant by many years? Thanks

Answer:

Cigarette smoking increases the risk of lung cancer by 10-30 fold compared with nonsmokers.   The chance of developing lung cancer is proportional to the total lifetime consumption of cigarettes, age at which one starts smoking, degree of inhalation, tar and nicotine content of the cigarettes, and the use of unfiltered cigarettes.  Other factors such as second hand smoke, inhalation of various other chemicals, dusts, or fumes may also predispose to the development of lung cancer.

The risk of developing lung cancer remains elevated in smokers compared with nonsmokers even after quitting cigarettes.  It is estimated that 15 years after quitting smoking there is an 80-90% reduction in risk compared to persistent smokers.

Thus, it appears that smoking increases the lifelong risk of lung cancer even if one quits.  The more of the risk factors that one has the higher that risk remains and conversely, the fewer risk factors one has, the less likely that individual is to develop lung cancer.

The best thing is never to start smoking and the next best to quit smoking.

For more information:

Go to the Lung Center health topic.