Smoking and Lung Cancer
by Beth G. Hodges, MD

Smoking and lung cancer go together like Fred and Ginger, like peanut butter and jelly, like Santa Claus and his reindeer. People who smoke are over twenty times more likely to develop lung cancer, and cigarette smoking is directly linked to about 90% of all lung cancers. More compelling evidence of a cause and effect relationship is rare to find in this world, yet people still continue to pick up the habit, usually as teenagers.

In the United States alone, 20% of all adult women and 25% of all adult men smoke, and these numbers are even higher in other developed countries throughout the world. Greece and Japan have the highest smoking rates globally. On average, about one-third or 33% of all adult males smoke throughout the world. In the United States, the percentage of adults who smoke has dropped significantly since the 1960's, mostly due to more people quitting than to fewer people picking up the habit.

Tobacco smoke contains about 4000 different carcinogens, which are chemicals that can cause cancer. They do this by damaging genes that control cell growth, causing too rapid growth to be contained.

Contrary to popular thought, lower tar cigarettes do not cause fewer lung cancers. There is also a popular belief that pipe and cigar smoke are less toxic. This assumption holds only a minimum of truth.

The risk of lung cancer for a smoker increases with the number of cigarettes smoked over the amount of time. Risk increases significantly once a person reaches a 30 "pack year" history." That would be calculated as a person who smokes one pack per day for 30 years or 2 packs per day for 15 years.

Is the risk of lung cancer ever lowered if the person quits smoking? Yes, by fifteen years out from the "quit date," the risk of cancer has lowered almost to that of a nonsmoker.

The facts about smoking and lung cancer are quite clear. Lung cancer, difficult to treat and almost impossible to cure, almost exclusively occurs in smokers or people heavily exposed to secondhand tobacco smoke. The risk for smokers who have a family history of lung cancer is even higher. The best way to avoid dying from lung cancer is to never get it in the first place--and that means quit smoking or don't start.

Published - September, 2009