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PET/CT & Lung Cancer
Lung cancer is the leading cause of cancer death and it is estimated that during
their lifetime, 1 in 21 women will develop lung cancer and 1 in 11 men will
develop this disease.
Lung cancer occurs when lung cells become abnormal and form more cells in an
uncontrolled manner. A tumor, which is a mass of tissue, develops out of these
extra cells and can either be benign (non-cancerous) or malignant (cancerous).
Although, there are a variety of types of lung cancer, this disease can be
classified in two groups:
Small cell lung cancer (SCLC): cancer cells are small but quickly form large
tumors that can progress to other parts of the body such as the lymph nodes,
brain, liver, and bones. Also known as oat cell cancer, SCLC accounts for approximately
20% of all lung cell cancers.
Non-small cell lung cancer (NSCLC): the most common form of lung cancer that
incorporates a variety of cancer sub-types such as Squamous cell carcinoma,
adenocarcinoma, and large cell carcinoma. This type of cancer also spreads to
other parts of the body but tends to progress slowly to different parts of the
body slower than SCLC.
The principal cause of lung cancer is cigarette smoking. Before cigarette smoking
became popular in the early 20th century, lung cancer was a rare occurrence.
However, cases of lung cancer have exploded over the last century with an estimated
87% of lung cancer cases stemming from smoking.
Cigarette smoke contains over 4,000 different chemicals and many of these cancers
have been proven to be carcinogens (cancer-causing substances). The probability
of lung cancer increases with the amount of time and quantity an individual
smokes.
Additionally, the use of smokeless tobacco products and the smoking of other
forms of tobacco products are major causes of lung cancer.
Another major cause of lung cancer is second-hand smoke, which is a byproduct
of smoking. Chemicals present in tobacco smoke affect nonsmokers who are inhaling
the smoke, and second hand smoke has been identified as causing approximately
3,000 lung cancer deaths per year. Second hand smoke has also been identified
as causing approximately 50,000 deaths from heart disease per year.
The second biggest cause of lung cancer is exposure to radon: an invisible,
odorless, and radioactive gas. Radon gas is commonly found in mines as well
as in the home. It often emerges from soil underneath a building that enters
through gaps and cracks in a building’s foundation or insulation. Radon can
also enter a home through other openings such as pipes, drains, and walls. Currently,
it is estimated that radon exposure makes up 12% of all lung cancer deaths,
causing between 15,000 and 22,000 lung cancer deaths per year.
An additional cause of lung cancer is on-the-job exposure to carcinogens. The
most common carcinogen is asbestos, (a substance commonly used in shipbuilding,
insulation work, and brake repair) which if inhaled can cause cell damage that
increases the potential of lung cancer. Additional carcinogens that are often
found on work sites include: uranium, arsenic, and certain petroleum products.
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