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Lung cancer is one of the most fatal cancers worldwide,
causing up to three million deaths annually. Only one in ten patients
diagnosed with this disease will survive the next five years. Although this
was an illness that previously affected predominantly men, lung cancer rate
for women has been increasing in the last few years because of the rising
ratio of female to male smokers. In many developing countries, public
education about the dangers of cigarette smoking and effective cessation
programs has contributed to the slowly falling rate of incidence of lung
cancer. Nevertheless, lung cancer still remains to be the most common form
of cancer in men worldwide and the fifth most common form of cancer in
women.
Lung cancer like all other cancers, results from abnormality in the body’s
basic unit of life, the cell. Normally, the body maintains a system checks
and balances on cell growth so that cells divide to produce new cells only
when needed. Interruption in the balance of this system causes an
uncontrolled division of cells that eventually forms a mass known as a
tumor. Any of the tissues in the lung can become cancer, but most commonly,
lung cancer comes from the lining of the bronchi. Since this disease tends
to spread very early in its course, it is very life-threatening and one of
the most difficult cancers to treat. Although it can spread to any organ in
the body, the adrenal glands, liver, brain, and bone, are the most common
lung cancer metastases.
Recent research point to the factor with the greatest impact on risk of lung
cancer is long-term exposure to inhaled carcinogens. Most common of which is
exposure to tobacco smoke. The occurrence of lung cancer is strongly linked
with cigarette smoking, with about 90% of the disease arising as a result of
tobacco used. The numbers of cigarettes smoke over time increases the risk
of lung cancer. Among those who smoke two or more packs of cigarettes per
day, one in seven will die of lung cancer. Passive smoking or inhalation of
tobacco smoke from other smokers sharing or working quarters, is also an
established risk factor for the development of the disease.
Non-smokers who
reside with a smoker have 24% increase risk for developing lung cancer
compared with non-smokers. In the U.S. an estimated 3,000 lung cancer deaths
that occur each year are attributed to passive smoking. Exposure to asbestos
fiber, silicate fibers that can persist for a lifetime in lung tissue
following exposure to asbestos, also increases the risk of the disease.
Radon gas is also a known cause of the disease with an estimated 12% of lung
cancer deaths. Familial predisposition or genetic susceptibility is also one
cause of lung cancer, studies have shown that the disease is more likely to
occur in both smoking and non-smoking relatives of those who have had lung
cancer than in the general population.
The presence of certain lung
diseases, particularly chronic obstructive pulmonary disease (COPD) is
associated with a slightly increased risk for development of lung cancer.
Air pollution from vehicles, industry, and power plants, can raise the
likelihood of developing the disease in exposed individuals.
What are the signs of lung cancer?
The early stages of the disease may not have any symptoms, but as the tumor
grows in size, it can produce a variety of symptoms that includes:
* cough (especially one that doesn't go away or gets worse in character)
* chest pain
* shortness of breath
* coughing up blood or bloody phlegm
* new onset hoarseness or wheezing
* recurrent problems with pneumonia or bronchitis
* weight loss
* loss of appetite
* fatigue
* bone pain
* dizziness or double vision
* numbness or tingling in your arms or legs
* turning yellow (jaundice)
Treatment of lung cancer can involve a combination of surgery, chemotherapy,
and radiation therapy as well as newer experimental methods, but prevention
of the development of the disease through smoking cessation is most
important.
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