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Lung Cancer
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Lung cancer is responsible for more cancer related
deaths in the U.S. than any other cancer. For a
perspective on the magnitude of the problem, in the year
2000, more than 180,00 men were diagnosed with prostate
cancer. In that same year, nearly 32,000 men died of the
disease. Corresponding numbers for women with breast
cancer were 182,200 and 40,800, respectively. In the
year 2000, the number of men and women diagnosed with
lung cancer were 89,500 and 74,600, respectively, while
the number of deaths for men and women were 79,300 and
67,600, respectively. To summarize, the most common
cancers diagnosed in men and women totaled 362,600 with
72,700 deaths due to these diseases. For lung cancer, a
total of 164,100 diagnoses were made with 146,900 people
dying of the disease. Stated another way, for half the
number of diagnosed cases, there were twice as many
deaths. Lung cancer is unquestionably lethal.
Cigarette smoking is the most significant risk factor.
An objective description of the extent of this risk
factor in an individual is quantified as “pack-years”.
This is simply calculated multiplying the number of
years an individual has smoked by the number of packs
per day smoked. For example, someone who has smoked 1
pack per day for 20 years has a 20 pack-year history of
cigarette smoking. A person who has smoked 2 packs per
day for 20 years has the same 40 pack-year history as
one who has smoked 1 pack per day for 40 years. The risk
of developing lung cancer increases dramatically from a
10 pack-year history to a 40 pack-year history and
above. Approximately 90% of all lung cancer could be
avoided if those who smoke never started. A smoker’s
risk for developing lung cancer can be reduced by
stopping, but the interval of time to reduce the risk to
near normal is lengthened with a greater pack-year
history.
Other risk factors include exposure to asbestos, radon
(a radioactive gas created by decay of the radioactive
element radium that has had medical uses in the past, or
can occur naturally), prior history of tuberculosis and
other chronic lung infections, and some industrial
chemicals. Second hand smoke is controversial as a
causative agent, and is highly dependant on proximity
and duration of exposure. |
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Lung cancer results from the
uncontrolled growth of abnormal cells in the lungs.
It is important to understand the difference between
PRIMARY lung cancer from
metastatic cancer to the
lung. Metastatic, or secondary, cancer is a malignancy
that starts in another organ of the body, and spreads
through the blood stream to settle and grow in the
lungs. This site is about primary lung cancer, in
other words, cancer that has its origins in the lungs.
90% of lung cancer fall into one of two groups: Small
Cell or Non-small Cell. These terms refer to
microscopic appearance of the cancer—not the size of
the cancer itself.
Treatment for lung cancer is determined by the type of
cancer, and by the “Stage” of the disease, that is,
how far the cancer has spread through the body.
Treatment decisions are also influenced by a patient’s
general health and the presence of other medical
problems. Below is the staging system for Non-small
Cell lung cancer. |
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A number of tests may be performed for this assessment.
These tests may include routine blood work, Chest X-ray,
bronchoscopy, Computed Tomography (CT) scans of the
chest, abdomen, pelvis, and/or brain, Magnetic Resonance
Imaging (MRI) of the brain, nuclear medicine bone scan,
and/or a Positron Emission Tomography (PET) scan, with
perhaps other tests as indicated to be needed for a
specific circumstance |
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Stage I:
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This is the earliest stage.
The cancer is small, and limited to the lung.
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Stage II:
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The cancer involves lymph nodes behind the
breast bone in the center
of the chest.
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Stage III:
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Extensive involvement of the lymph nodes.
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Stage IV:
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Cancer outside the chest, usually
in the brain liver or bones.
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Surgery is often curative in the
early stages of lung cancer. However, with advancing
stage, surgery is often impossible and combinations of
chemotherapy and radiation are used instead. Also,
surgery is only possible in patients who are healthy
enough to tolerate it.
Chemotherapy: Historically lung cancer was not
thought to be very sensitive to the effects of
chemotherapy. However, with newer drugs to manage side
effects, combinations of different chemotherapy drugs
can be given which produce better results. Chemotherapy
can help shrink cancers making inoperable tumors
operable. It can slow the growth of established cancers
and help keep them from spreading. And, it can be given
in combination with radiation to make the radiation more
effective. Side effects depend upon the type of
chemotherapy drugs chosen. Ask your Medical Oncologist
for these details.
Click here to
meet the Medical Oncologists at our cancer care center
at Tampa, Florida.
Radiation is sometimes used before surgery to
shrink the tumor. It can also be give after surgery if
any remaining cancer cells are thought to remain. And,
it is often used in combination with chemotherapy
instead of surgery when tumors are too advanced to
remove, or patients are too unwell to have an operation.
Side effects include local skin irritation, and sore
throat (due to radiation of the esophagus). In most
patients there is also some damage to normal lung
surrounding the tumor. Patients must have adequate lung
function to undergo lung radiation. Internal radiation (High
Dose Rate Brachytherapy) is used in situations
when a cancerous tumor is growing inside, and blocking
an airway. A radioactive source on a cable is actually
passed through the windpipe into the blocked section of
the lung. Using this technique, a high dose of radiation
can be delivered directly to the cancer, hopefully
opening up the blocked airway while sparing surrounding
normal lung from significant radiation exposure.
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Small Cell lung cancer
accounts for about 20% of all lung cancer cases and is
uniquely sensitive to chemotherapy. Treatment of Small
Cell lung cancer generally requires both chemotherapy
and radiation therapy. The staging system above does not
apply. Rather, patients are considered to have "Limited"
or "Extensive" disease
depending upon whether cancer has grown outside of the
chest. Limited disease is potentially curable with
aggressive therapy.
Chemotherapy is the primary treatment for limited stage
small-cell cancer of the lung. Small-cell cancers are
highly responsive to chemotherapy, and although more
than 80% of patients respond completely to chemotherapy,
nearly all cancers eventually recur in the lung.
Radiation therapy to the chest significantly reduces
that risk and is now an integral part of the treatment.
However, even when the tumor in the chest disappears
completely, approximately 30% of patients will
eventually develop metastatic cancer in the brain. This
occurs because chemotherapy cannot penetrate the brain
well. Thus, the brain acts as a
sanctuary site for cancer cells. Prophylactic
radiation treatments of the brain in moderate doses have
been shown to drastically reduce the risk that cancer
will relapse in the brain and probably improves the
patient's ultimate chance of survival.
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The majority of cancer related
deaths result from the failure to prevent and control
metastatic disease. A relatively new area of
investigation to improve this problem is gaining some
momentum. It appears that cancer cells create a chemical
that promotes new blood vessel growth, a process called
angiogenesis, so that oxygen and nutrients can be
delivered for growth, and waste materials can be carried
away. A class of new drugs, angiogenesis inhibitors,
under investigation is designed to stop that new blood
vessel growth to starve these cancer cells. Actually,
one of these drugs has been around for decades. It was a
drug commonly used for the treatment of nausea in
pregnant women with disastrous consequences for the
developing baby. THALIDOMIDE is making a comeback. It
has been studied and has been found to show anticancer
activity in other cancers, especially a cancer known as
multiple myeloma. A new angiogenesis inhibitor, IRESSA,
is currently under study for the treatment of metastatic
lung cancer.
If you haven’t done so already, stop smoking! You will
feel better and you will tolerate your treatment better.
The best way to survive lung cancer is not to get it in
the first place.
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10 Year
Cancer Study - click here for Acrobat PDF document
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