Although lung cancer is the
leading cause of cancer deaths in the United States, it is also one of
the most preventable kinds of cancer. At least four out of five cases
are associated with cigarette smoking. More than 170,000 people in the
U.S. are diagnosed with lung cancer each year, most between the ages of
40 and 70.
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What causes lung cancer?
Cigarette smoke has 4000 chemicals and of these, over 40 are known
to cause cancer. Normal human
cells become cancer cells when exposed to carcinogens.
The risk of developing lung cancer in humans is proportional to the number
of cigarettes smoked. Smokers are 8-20 times more likely to develop lung cancer
compared to people who have never smoked.
here is a normal, inflated lung to compare to the smoker's lung below.
This is what your lungs should look like.
on the left is a smoker's lung. Cigarette smoke has tars and
chemical agents in it that irritate the lungs and cause lung cancer
to form. The cancer cells in this picture are shown by the whitish
area in an otherwise blackened lung.
Why is lung cancer a serious problem?
Over 300,000 people die from lung cancer in the United
States alone. The economic loss is calculated to be over two billion dollars
Since the majority of lung cancer is diagnosed at a relatively late stage,
only 10% of all lung cancer patients are ultimately cured. If the patient
cannot be cured by surgery at the time the cancer is found, there is a
50% chance that death will occur in less than one year.
What are the symptoms of lung cancer?
In its early stages, lung cancer normally has no symptoms. Most lung
cancers begin to grow silently, without any symptoms. Patients with lung
cancer often do not develop symptoms until the cancer is in an advanced
stage. The actual time from when one cell becomes cancerous until it is
large enough to be diagnosed or produce symptoms may take as long as 10
to 40 years. When symptoms start to appear, they are usually caused by
blocked breathing passages or by the spread of cancer to other parts of the
Smoking causes cancer. The occurrence of lung cancer can be reduced
by not smoking.
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