What is the link between smoking and lung cancer?

Joseph I. Miller Jr., MD
Thoracic Surgery (Cardiothoracic Vascular)
The exact link is not entirely known.  There is more to it than just nicotine in the tobacco and smoking.  What is know is that there is a clear association and risk with the smoking and risk of many types of cancers. The risk also goes away quickly with stopping.
Dr. Michael Roizen, MD
Internal Medicine

Lung cancer is rare without smoking or radon or articulate measures such as being exposed to arsenic in mining, and other things like that.  More than 90%, some say as many as 97%, of lung cancer is related to smoking.  Clearly, not everyone who smokes gets lung cancer.  It is a vulnerability, so if your father developed it, or your mother developed it, you may have a risk for it, but the heat and inflammation caused by smoking, and the particulates caused by smoking set up an inflammatory reaction that in specific DNA triggers cancer.  

The risk for lung cancer from smoking is dependent on the quantity of cigarettes smoked, as well as the duration. The tar contained in cigarettes is a cancer-causing agent as are as many as 50 other chemicals contained in cigarette smoke.
Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
The link between smoking and lung cancer is a pretty strong one. Studies have shown that if you compare people who have smokers to nonsmokers, long-term smokers vs. lifetime nonsmokers, smokers are 10 to 30 times more likely than nonsmokers to develop lung cancer.

Another way to think about the smoking-lung cancer connection: Smoking accounts for about 90% of all cases of lung cancer, and lung cancer is the primary cause cancer-related deaths in the U.S. So, if you don't want lung cancer, don't smoke. It's as simple as that. And if you do smoke, quit. Not smoking isn't a guarantee that you won't get lung cancer, but it will lower your chances significantly.
Smoking is the No. 1 cause of lung cancer. About 80% of lung cancers are thought to be the result of smoking, according to the American Lung Association. Cigarette smoke contains more than 4,000 different chemicals. About 60 of these are carcinogens, or cancer-causing substances. Hundreds of other substances in cigarettes increase the cancer-causing power of these chemicals.

Lung cancer occurs most often in people over 50 who have smoked cigarettes for a long time. The more you smoke and the longer you smoke, the greater your risk of lung cancer.

But it's never too late to quit. If you stop smoking, your risk decreases steadily each year. That's because your body replaces the damaged cells with normal ones. However, the risk never completely returns to the same risk as that of people who never smoked. Since stop smoking (smoking cessation) efforts in the United States have been reasonably successful, lung cancer is now very often thought of as a disease of former smokers.
Elwyn C. Cabebe, MD
Hematology & Oncology
Smoking can increase your risk of developing lung cancer due to the toxins from the smoke itself. Watch as oncologist Elwyn Cabebe, MD, of Good Samaritan Hospital describes how smoking can also harm lung function and cause other diseases to develop.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.