What
Is Lung Cancer?
 The
lungs are 2 sponge-like organs found in the chest. The
right lung has 3 sections, called lobes. The left lung
has 2 lobes. The left lung is smaller because the heart
takes up more room on that side of the body. The lungs
bring air in and out of the body, taking in oxygen and
getting rid of carbon dioxide gas, a waste product.
The lining around the lungs, called the pleura, helps
to protect the lungs and allows them to move during
breathing. The windpipe (trachea) brings air down into
the lungs. It divides into tubes called bronchi (or
just one, bronchus) which divide into smaller branches
called bronchioles. At the end of these small branches
are tiny air sacs known as alveoli.
Most lung cancer starts in the lining of the bronchi,
although it can also start in other parts of the lung.
Lung cancer often takes many years to develop. First,
there may be areas of pre-cancerous changes in the lung.
These changes are not a mass or tumor. They can't be
seen on an x-ray and they don't cause symptoms. But
these changes can be found by special tests of cells
in the lining of the airways of lungs damaged by smoke.
As these pre-cancerous areas go on to become true cancer,
they may make chemicals that cause new blood vessels
to form nearby. These new blood vessels nourish the
cancer cells and allow a tumor to form. Finally, the
tumor becomes large enough to show up on an x-ray.
Once lung cancer occurs, cancer cells can break away
and spread to other parts of the body in a process called
metastasis. Lung cancer is a life-threatening disease
because it often spreads in this way before it is found.
Types of Lung Cancer
There are 2 main types of lung cancer and they are treated
differently.
• small cell lung cancer (SCLC)
• non-small cell lung cancer (NSCLC)
If the cancer has features of both types, it is called
mixed small cell/large cell cancer. The information
here only covers non- small cell lung cancer. Small
cell lung cancer is covered in a separate document.
Other types of tumors can grow in the lungs as well.
Some of these are not cancer and others are cancerous.
Carcinoid tumors, for example, are slow-growing and
usually cured by surgery. The American Cancer Society
has more information about lung carcinoid tumors. To
learn about these tumors, see our document "Lung Carcinoid
Tumor."
Non-small Cell
Lung Cancer (NSCLC)
About 85% of all lung cancers are of the non-small cell
type. There are 3 sub-types of NSCLC. The cells in these
sub-types differ in size, shape, and chemical make-up.
• squamous cell carcinoma: about 25% to 30% of
all lung cancers are of this kind. They are linked to
smoking and tend to be found near the bronchus.
• adenocarcinoma: this type accounts for about
40% of lung cancers. It is usually found in the outer
part of the lung.
• large-cell undifferentiated
carcinoma: about 10% to 15% of lung cancers are this
type. It can start in any part of the lung. It tends
to grow and spread quickly.
How
Many People Get Non-small Cell Lung Cancer?
Lung cancer is the leading cause of cancer death for
both men and women. More people die of lung cancer than
of colon, breast, and prostate cancers combined. Lung
cancer is fairly rare in people under the age of 45.
In 2006 there will be about 174,470 new cases of lung
cancer (both small cell and non-small cell) in the United
States: 92,700 among men and 81,770 among women. About
162,460 people will die of this disease: 90,330 men
and 72,130 women.
The average lifetime chance that a man will develop
lung cancer is 1 in 13. For a woman it is 1 in 17. The
rate of non-small cell lung cancer is dropping rapidly
in men and much more slowly in women.
About 6 out of 10 people with lung cancer die within
1 year of finding out they have lung cancer. Between
7 and 8 will die within 2 years. But some people are
cured. Right now there are about 330,000 long-term lung
cancer survivors.
What
Causes Non-small Cell Lung Cancer?
A risk factor is anything that increases a person's
chance of getting a disease such as cancer. Different
cancers have different risk factors. Some risk factors,
such as smoking, can be controlled. Others, like a person's
age or family history, can't be changed. Several factors
can increase the risk of lung cancer.
Smoking is by far the leading risk factor for lung cancer.
Tobacco smoke causes more than 8 out of 10 cases of
lung cancer. The longer a person has been smoking and
the more packs per day smoked, the greater the risk.
If a person stops smoking before lung cancer develops,
the lung tissue slowly returns to normal. Stopping smoking
at any age lowers the risk of lung cancer.
Cigar and pipe smoking are almost as likely to cause
lung cancer as is cigarette smoking. There is no evidence
that smoking low tar cigarettes reduces the risk of
lung cancer.
People who don't smoke but who breathe the smoke of
others also have a higher risk of lung cancer. Non-smoking
spouses of smokers, for example, have a 30% greater
risk of developing lung cancer than do spouses of nonsmokers.
Workers exposed to tobacco smoke in the workplace are
also more likely to get lung cancer. The cancer-causing
effects of tobacco smoke appears to affect certain people
more than others.
Hookah smoking (use of a water pipe) has become popular
among young people. Although there is less tobacco in
the product used for hookahs, hookah smoking is not
safe. The smoke contains the same cancer-causing substances
as cigarettes, including nicotine which is addictive.
Arsenic, if found in high
levels in drinking water, may increase the risk of lung
cancer. The effect is even greater for smokers.
Asbestos is another risk factor
for lung cancer. People who work with asbestos have
a higher risk of getting lung cancer. If they smoke
as well, the risk is greatly increased. Although asbestos
was used for many years, the government has now nearly
stopped its use in the workplace and in home products.
While it is still present in many buildings, it is not
thought to be harmful as long as it is not released
into the air.
Another type of cancer linked to asbestos (mesothelioma)
can start in the lining of the lung. The American Cancer
Society has information about this type of cancer through
our toll-free number or on our Web site.
Radon is a radioactive gas made by the natural breakdown
of uranium, which is found at higher than normal levels
in the soil in some parts of the United States. Radon
can't be seen, tasted, or smelled. Radon can become
concentrated indoors and create a possible risk for
cancer. Smokers are especially sensitive to the effects
of radon. State and local offices of the EPA (Environmental
Protection Agency) can provide information about how
to test for radon in the home. A document with details
about radon is available from the ACS.
Cancer-causing agents in the workplace
include the following:
• uranium
• beryllium
• vinyl
chloride
• nickel chromates
• coal
products
• mustard gas
• chloromethyl
ethers
• gasoline
• diesel exhaust
People who work with these substances should be very
careful to avoid exposure as much as possible.
Marijuana cigarettes
have more tar than regular cigarettes. Many of the cancer-causing
substances in tobacco are also found in marijuana. Marijuana
is also inhaled very deeply and the smoke is held in
the lungs for a long time.
Medical reports suggest that marijuana can cause cancers
of the mouth and throat. But because marijuana is an
illegal substance it is not easy to gather information
about its effects on the body.
Radiation
treatment to the lung: People who have had
radiation to the chest to treat cancer are at higher
risk for lung cancer, especially if they smoke. But
non-smoking women who have radiation to the breast after
surgery for breast cancer do not have a higher risk
of lung cancer.
Diseases
such as silicosis and berylliosis (caused by breathing
in certain minerals) also increase the risk of lung
cancer.
Personal and
family history: If you have had lung cancer,
you have a higher risk of getting another lung cancer.
Brothers, sisters, and children of people who have had
lung cancer may have a slightly higher risk themselves.
Diet: Some reports
suggest that a diet low in fruits and vegetables might
increase the risk of lung cancer in people who are exposed
to tobacco smoke. It may turn out that fruits and vegetables
help protect against lung cancer.
Air pollution: In some cities, air pollution may increase
the risk of lung cancer. But the risk is still far less
than that caused by smoking.
During the past few years, scientists have made great
progress in understanding how risk factors produce certain
changes in the DNA of lung cells, causing the cells
to become cancerous. DNA is the genetic material that
carries the instructions for nearly everything our cells
do.
Current research in this field is aimed at developing
tests that can find lung cancers at an early stage by
spotting DNA changes. But these tests are not yet ready
for routine use. Therefore, doctors stress avoiding
tobacco smoke and the other risk factors listed above.
Can Non-small Cell Lung
Cancer Be Prevented?
The best way to prevent lung cancer is not to smoke
and to avoid people who do. If you already smoke, you
should try to quit. You should also avoid breathing
in other people's smoke.
A good diet with lots of fruits and vegetables may also
help prevent lung cancer.
Some people who get lung cancer do not have any known
risk factors, so it is not possible to prevent all cases
of lung cancer.
How Is
Non-small Cell Lung Cancer Found?
Since most people with early lung cancer do not have
any symptoms, only a small number of lung cancers are
found at an early stage. When lung cancer is found early,
it is often because of tests that were being done for
something else.
Screenings
Tests for Lung Cancer
Screening is the use of tests or exams to find a disease
(such as cancer) in people who don't have any symptoms.
Because lung cancer often spreads beyond the lungs before
it causes symptoms, a good screening test to find lung
cancer early could save many lives.
Chest x-rays and checking sputum (spit) under a microscope
to look for cancer cells have been studied for several
years. These studies have shown that this kind of screening
does not find many lung cancers early enough to improve
a person's chance for a cure. For this reason, lung
cancer screening is not usually advised even for people
at higher risk, such as those who smoke.
Recently an x-ray method called spiral CT scanning has
shown some promise in finding early lung cancer in smokers
and former smokers. But it has not yet known if this
test will lower the chances of dying from lung cancer.
One major problem is that it finds a lot of things that
turn out not to be cancer. This leads to unnecessary
tests such as biopsies and even surgery.
To find out how useful this test might be, a large study
is going on. It is called the National Lung Screening
Trial (NLST). When the results come out, we will have
a better idea whether spiral CT scanning will catch
lung cancer early enough to save lives. Until then,
people who are interested in testing should understand
the pros and cons of this test. And people who smoke
should keep in mind that the best way to avoid dying
from lung cancer is to stop smoking.
Common
Signs and Symptoms of Lung Cancer
Although most lung cancers do not cause symptoms until
they have spread, you should report any of the following
to your doctor right away. Often these problems are
caused by something other than cancer. But if lung cancer
is found, getting treatment right away could help you
live longer and relieve symptoms. The most common symptoms
are:
" a cough that does not go away
"
chest pain, often made worse by deep breathing
" hoarseness " weight loss and loss of appetite
" bloody or rust-colored sputum (spit or phlegm)
" shortness of breath
" infections such as bronchitis
and pneumonia that keep coming back
" new onset
of wheezing
When lung cancer spreads to distant organs, it may cause:
" bone pain
" weakness or numbness of
the arms or legs
" dizziness or seizure
"
yellow coloring of the skin and eyes (jaundice)
" masses near the surface of the body, caused by cancer
spreading to the skin or to lymph nodes in the neck
or above the collarbone
If you have any of these problems, you should see a
doctor right away.
Less often, there are some other clusters of symptoms
(called syndromes) that can point to a possible lung
cancer.
If Non-small
Cell Lung Cancer is Suspected
After asking questions about your health and doing a
physical exam, your doctor might want to do some of
the following:
Imaging
Tests
There are a number of different tests that can produce
pictures of the inside of your body. Some of these are
used to find lung cancer and to see if it has spread
Chest x-ray: This
is the first test your doctor will order to look for
any spot on the lungs. It is a plain x-ray of your chest.
If the x-ray is normal, you most likely do not have
lung cancer. If anything looks suspicious, the doctor
may order more tests.
CT
scan (computed tomography): A CT scan is a
special kind of x-ray. Instead of taking just one picture,
the CT scanner takes many pictures as it moves around
you. A computer then combines these pictures into an
image of a slice of your body. Often after the first
set of pictures is taken you will get an injection of
a "dye" that helps to outline structures in your body.
Then a second set of pictures is taken. CT scans take
longer than normal x-rays, but they are getting faster
all the time.
The CT scan will give the doctor precise information
about the size, shape, and place of a tumor. It can
also help find enlarged lymph nodes that might contain
cancer. CT scans are also used to find tumors in other
organs that might be affected by the spread of lung
cancer
MRI scan (magnetic
resonance imaging): MRI scans use radio waves
and strong magnets instead of x-rays. MRI scans take
longer than x-rays-often up to an hour. Also, you have
to be placed inside a tube-like machine, which upsets
some people. MRI scans are useful in finding lung cancer
that has spread the brain or spinal cord.
PET scan (positron emission tomography):
PET uses a form of sugar that contains a radioactive
atom. Cancer cells in the body absorb large amounts
of the sugar. A special camera can then detect the radioactivity.
This test can show whether the cancer has spread to
the lymph nodes. It is also helpful in telling whether
a spot on your chest x-ray is cancer. PET scans are
also useful when the doctor thinks the cancer has spread,
but doesn't know where. Newer machines combine a CT
and a PET scan to even better pinpoint the tumor.
Bone scan: For a bone scan a small amount of radioactive
substance is injected into a vein. The amount used is
very low and causes no long-term effects. This substance
builds up in areas of bone that may be abnormal because
of cancer. But other problems can also cause suspicious
results. Bone scans are only done in patients with non-small
cell lung cancer when other tests or symptoms suggest
that the cancer has spread to the bones.
Other
Tests
The following tests can be used to confirm whether something
seen on an imaging test is really lung cancer. These
tests are also used to decide the exact type of lung
cancer and how far it may have spread.
Sputum
cytology: A sample of phlegm (spit) is looked
at under a microscope to see if cancer cells are present.
Needle biopsy: After the skin is numbed, a long, thin
needle is placed into the tumor in the lung to remove
a piece of tissue. The doctor guides the needle using
either a method something like an x-ray (fluoroscopy)
or a CT scan. The tissue is looked at in the lab to
see if cancer cells are present. One possible problem
with this method is that air may leak out of the lung
at the biopsy site. This can cause the lung to collapse
and cause trouble breathing. It is treated by putting
a small tube into the chest space and sucking out the
air over a day or two.
Bronchoscopy (bron-kos-kuh-pee): A lighted, flexible
tube is passed through the mouth into the bronchi. This
test can help find tumors or it can be used to take
samples of tissue or fluids to see if cancer cells are
present. You will need to be sedated for this exam.
Endobronchial (en-do-brong-kee-ul)
ultrasound: In this technique the bronchoscopy
tube is fitted with an ultrasound emitter and receiver
at its tip. This may help to measure the size of the
tumor and to spot enlarged lymph nodes
Endoscopic
esophageal (en-do-skop-ic eh-sof-uh-JEE-uhl) ultrasound
(EUS): In this technique a flexible fiberoptic
scope is fitted with an ultrasound emitter and receiver
at its tip and passed into the esophagus. This is done
with light sedation. The esophagus is close to some
lymph nodes inside the chest, and lung cancer can spread
to these lymph nodes. Ultrasound images taken from inside
the esophagus can be helpful in finding large lymph
nodes inside the chest that might contain metastatic
lung cancer.
Mediastinoscopy (me-dee-uh-stine-AHS-kuh-pee) and mediastinotomy
(me-dee-uh-stine-AHT-uh-mee): For eiter of these, you
will have general anesthesia (be put into a deep sleep).
With mediastinoscopy a small cut is made in your neck
and a hollow lighted tube is placed behind the sternum
(breastbone). Special instruments, operated through
this tube, can be used to take a tissue sample from
the lymph nodes along the windpipe and the major bronchial
tube areas. Looking at the samples under a microscope
can show whether cancer cells are present.
Mediastinotomy is used to remove samples of mediastinal
lymph nodes while the patient is under general anesthesia.
Unlike mediastinoscopy, the surgeon opens the chest
cavity by making a small incision beside the sternum.
This allows the surgeon to reach lymph nodes that can't
be reached by standard mediastinoscopy.
Thoracentesis
(thor-uh-sen-tee-sis) and thoracoscopy (thor-uh-kos-kuh-pee):
These tests are done to check whether fluid around the
lungs is caused by cancer or by a condition such as
heart failure or an infection. For thoracentesis, the
skin is numbed and a needle is placed between the ribs
to drain the fluid, which is checked for cancer cells.
Thoracoscopy uses a thin, lighted tube connected to
a video camera and monitor to look at the space between
the lungs and the chest wall.
Blood
tests: A complete blood count (CBC) shows
whether your blood has the correct number of different
cell types. This test will be done often if you are
treated with chemotherapy because these drugs can affect
the blood-forming cells of the bone marrow. Other blood
tests can spot problems in different organs such as
the liver and bones.
How
Is Non-small Cell Lung Cancer Treated?
If you have lung cancer, your treatment choices are
surgery, radiation therapy, and chemotherapy. More than
one kind of treatment may be used, depending on the
stage of your cancer.
Your doctor will talk to you about treatment choices.
Give yourself time to absorb the information you have
learned. The most important factors to take into account
include the stage of the cancer, your overall health,
the likely side effects of the treatment, and the chance
of curing the cancer or extending your life. Age alone
should not be a barrier to treatment. Older people can
benefit from treatment as much as younger people as
long as their general health is good.
It is often a good idea to get a second opinion. A second
opinion can provide more information and help you feel
good about the treatment plan you choose.
Types of Treatment for Non-Small
Cell Lung Cancer
Surgery
Surgery may be used to remove the cancer along with
some of the lung tissue around it. Removing only part
of a lobe (section) of the lung is called a wedge
resection. If a whole lobe of the lung is removed,
the surgery is called a lobectomy.
If the entire lung is removed, the surgery is called
a pneumonectomy. Lymph nodes are also
removed so the doctor can see if the cancer has spread.
These operations are done with the patient asleep. A
hospital stay of 1 or 2 weeks is usually needed. There
will be some pain after the surgery because the surgeon
has to cut through the ribs to get to the lungs. Other
possible problems include bleeding, wound infections,
and pneumonia.
There is a new kind of surgery for people with early
stage lung cancer. It is called video-assisted chest
surgery. A tiny camera can be placed through a small
hole in the chest to help the surgeon see the tumor.
Only small incisions are needed, so there is less pain
after surgery. Another advantage of this surgery is
a shorter hospital stay - around 5 days. This approach
is most often used for tumors smaller than about one
and a half inches. The cure rate seems to be the same
as for standard surgery. The doctor who does this surgery
should have experience since it requires a lot of skill.
People whose lungs are in good condition (other than
the cancer) can often return to normal activities after
a lobe or even an entire lung is removed. But if they
also have problems such as emphysema or chronic bronchitis
(common among heavy smokers), after surgery they may
have shortness of breath when active.
For people who can't have the usual surgery because
of lung disease or other medical problems, or because
the cancer is widespread, other types of surgery (for
example, laser surgery) can be done to relieve symptoms.
Sometimes fluid collects in the chest and interferes
with breathing. This fluid can be removed through a
small tube placed in the chest. Then either talc or
some type of drug is placed into the chest. This will
start a reaction that will help seal the space and prevent
future fluid buildup.
Radiation
Therapy
Radiation therapy is treatment with high-energy rays
(such as x-rays) to kill or shrink cancer cells. The
radiation may come from outside the body (external radiation)
or from radioactive materials placed into or next to
the tumor (brachytherapy). External radiation is the
type most often used to treat lung cancer.
Radiation is sometimes used as the main treatment of
lung cancer. It might be used for people who are not
healthy enough to have surgery. For other patients,
radiation might be used after surgery to kill small
areas of cancer that can't be seen and removed during
surgery. Or it could be used on the brain to try to
prevent the spread of cancer there. Radiation can also
be used to relieve symptoms such as pain, bleeding,
trouble swallowing, or problems caused by the cancer
spreading to the brain.
Side effects of radiation could include mild skin problems,
nausea, vomiting, and tiredness. Often these go away
after a short while. Chest radiation may cause lung
damage and trouble breathing or swallowing.
Side effects of radiation therapy to the brain usually
become most serious 1 or 2 years after treatment. These
side effects could include memory loss, headaches, trouble
with thinking, and less sexual desire. These side effects,
though, are minor compared to those caused by a brain
tumor.
A special kind of radiation (called the gamma knife)
can be used instead of surgery if the cancer spreads
to the brain in only 1 spot. In this method, several
beams of radiation are focused on the tumor over the
span of a few minutes to hours. The head is held in
place with a rigid frame.
Chemotherapy
Chemotherapy is treatment with anticancer drugs given
into a vein or by mouth. These drugs enter the bloodstream
and reach throughout the body, making this treatment
useful for cancer that has spread (metastasized) to
organs beyond the lung. Several drugs may be given at
the same time.
Chemotherapy drugs kill cancer cells but they also damage
some normal cells, causing side effects. These side
effects depend on the type of drugs used, the amount
given, and the length of treatment. You could have some
of these short-term side effects
• loss
of appetite
• hair loss (temporary)
•
mouth sores
• loose stools (diarrhea)
• a higher risk of infection caused by a shortage
of white blood cells
• bruising or bleeding
after minor cuts caused by a shortage of blood platelets
• fatigue or shortness of breath caused by
low red blood cell counts
Some chemotherapy drugs can damage nerves. This can
cause numbness in the fingers and toes, and sometimes
the arms and legs may feel weak.
Most of these side effects go away when treatment is
over. If you have any problems with side effects, be
sure to tell your doctor or nurse, as there are often
ways to help.
There is a new drug (erlotinib) that works by keeping
cancer cells from growing. It is given, as a pill, to
some patients for whom chemotherapy is not working.
Side effects can include diarrhea, rashes, eye problems,
vomiting, loss of appetite, and tiredness.
For cancer cells to grow, they must form new blood vessels
to "feed" the tumor. There is a drug (Avastin) which
can keep new blood vessels from forming. It has been
shown to help people with advanced lung cancer live
longer when it was given along with chemotherapy. But
it causes bleeding, so it can't be used for patients
who are coughing up blood or whose cancer has spread
to the brain.
Non-Small
Cell Lung Cancer Survival by Stage (based on patients
from 1992-1993; AJCC Manual, 6th edition)
| Stage |
5-year Survival Rate |
| I |
47% |
| II |
26% |
| III |
8% |
| IV |
2% |
The 5-year survival rate refers to the percentage of
patients who live at least 5 years after their cancer
is found. Of course, some patients live much longer
than 5 years. Five-year relative survival rates means
that people who die of other causes are not included,
and the rate only includes people who die from lung
cancer
While these numbers provide an overall picture, keep
in mind that every person's situation is unique and
the statistics can't predict exactly what will happen
in your case. Talk with your cancer care team if you
have questions about your own chances of a cure, or
how long you might survive your cancer. They know your
situation best.
Clinical
Trials
Studies of promising new treatments are known as clinical
trials. A clinical trial is done only when there is
some reason to believe that the new treatment may be
of value to the patient. Clinical trials are needed
in order to find new and better ways to treat cancer.
Treatments used in clinical trials are often found to
have real benefits. The main questions the researchers
want to answer are:
• Is this treatment
helpful?
• Does it work better than the one
we're now using?
• What side effects does
it cause?
• Do the benefits outweigh the side
effects?
• Which patients are most likely to
find this treatment helpful?
Clinical trials are carried out in steps called phases.
Each phase is designed to answer certain questions
Phase I clinical
trials look at the best way to give a new treatment
and how much of it can be given safely. The main purpose
of a phase I study is to test the safety of the new
drug.
Phase II
clinical trials are designed to see if the drug works.
Patients are given the highest dose that doesn't cause
serious side effects and then watched closely to see
if there is an effect on the cancer.
Phase
III clinical trials compare the new treatment
with standard treatment. Large numbers of patients are
divided into two groups. The control group receives
standard treatment and the other group receives the
new treatment. Everyone is closely watched to see which
treatment is more effective. The study is stopped if
the side effects are too severe or if one group has
much better results than the other.
If you are in a clinical trial, you will have a team
of experts watching your progress very carefully. However,
there are some risks. No one knows in advance if the
treatment will work or exactly what side effects will
occur. That is what the study is designed to find out.
Keep in mind, though, that even standard treatments
have side effects.
Taking part in a clinical trial is completely up to
you. Even after joining a clinical trial, you are free
to drop out of the study at any time, for any reason.
Taking part in the study will not prevent you from getting
other medical care you may need.
Small
Cell Lung Cancer
About 15% of all lung cancers are the small cell type.
This cancer often starts in the bronchi near the center
of the chest. Although the cancer cells are small, they
can multiply quickly and form large tumors that can
spread widely through the body. This is important because
it means that treatment must include drugs to kill the
widespread disease. This kind of cancer is almost always
caused by smoking. It is very rare for someone who has
never smoked to have small cell lung cancer.
How Many People Get Lung Cancer?
Lung cancer is the leading cause of cancer death for
both men and women. More people die of lung cancer than
of colon, breast, and prostate cancers combined. Lung
cancer is fairly rare in people under the age of 45.
In 2006 there will be about 174,470 new cases of lung
cancer (both small cell and non-small cell) in the United
States: 92,700 among men and 81,770 among women. About
162,460 people will die of this disease: 90,330 men
and 72,130 women.
The average lifetime chance that a man will develop
lung cancer is 1 in 13. For a woman it is 1 in 17.
About 6 out of 10 people with lung cancer die within
1 year of finding out they have lung cancer. Between
7 and 8 out of 10 will die within 2 years. However,
some people are cured. Right now there are about 330,000
long-term lung cancer survivors.
What
Causes Small Cell Lung Cancer?
A risk factor is anything that increases a person's
chance of getting a disease, such as cancer. Different
cancers have different risk factors. Some risk factors,
such as smoking, can be controlled. Others, like a person's
age or family history, can't be changed. Many factors
can increase the risk of lung cancer.
 Smoking
is by far the leading risk factor for lung cancer. Tobacco
smoke causes more than 8 out of 10 cases of lung cancer.
The longer a person has been smoking and the more packs
per day smoked, the greater the risk. If a person stops
smoking before lung cancer develops, the lung tissue
slowly returns to normal. Stopping smoking at any age
lowers the risk of lung cancer.
Cigar and pipe smoking are almost as likely to cause
lung cancer as is cigarette smoking. There is no evidence
that smoking low tar cigarettes reduces the risk of
lung cancer.
People who don't smoke but who breathe the smoke of
others (called secondhand smoke) also have a higher
risk of lung cancer. Non-smoking spouses of smokers,
for example, have a 30% greater risk of developing lung
cancer than do spouses of nonsmokers. Workers exposed
to tobacco smoke in the workplace are also more likely
to get lung cancer.
Hookah smoking has become popular among young people,
who may believe it is safer than cigarettes. This is
not true. Hookah smoke contains the same cancer-causing
substances found in cigarettes, and the nicotine is
addictive and may lead to cigarette smoking in the future.
Asbestos is
another risk factor for lung cancer. People who work
with asbestos have a higher risk of getting lung cancer.
If they also smoke, the risk is greatly increased. Although
asbestos was used for many years, the government has
now nearly stopped its use in the workplace and in home
products. While it is still present in many buildings,
it is not thought to be harmful as long as it is not
released into the air.
Another type of cancer linked to asbestos (mesothelioma)
can start in the lining of the lung. The American Cancer
Society has information about this type of cancer through
our toll-free number or on our Web site.
Arsenic, if found in high levels in drinking water,
may increase the risk of lung cancer. The effect is
even greater for smokers.
Radon is a radioactive gas made by the natural breakdown
of uranium, which is found at higher than normal levels
in the soil in some parts of the US. Radon can't be
seen, tasted, or smelled. Radon can become concentrated
indoors and create a possible risk for cancer. Smokers
are especially sensitive to the effects of radon. State
and local offices of the EPA (Environmental Protection
Agency) can provide information about how to test for
radon in the home.
Other cancer-causing agents in the workplace include
the following:
" uranium
" beryllium
"
vinyl chloride
" nickel chromates
" coal products
" mustard gas
" chloromethyl ethers
"
gasoline
" diesel exhaust
People who work with these substances should be very
careful to avoid exposure as much as possible.
Marijuana cigarettes
have more tar than regular cigarettes. Many of the cancer-causing
substances in tobacco are also found in marijuana. Marijuana
is also inhaled very deeply and the smoke is held in
the lungs for a long time.
Medical reports suggest that marijuana could cause cancers
of the mouth and throat. But because marijuana is an
illegal substance it is not easy to gather information
about its effects on the body.
Radiation
treatment to the lung: People who have had
radiation to the chest to treat cancer are at higher
risk for lung cancer, especially if they smoke. Most
often these patients are those treated for Hodgkin disease
or women who receive radiation to the chest after a
mastectomy for breast cancer. But non-smoking women
who have radiation to the chest after lumpectomy surgery
for breast cancer do not have a higher risk of lung
cancer.
Diseases such as silicosis and berylliosis (lung problems
caused by breathing in certain minerals) also increase
the risk of lung cancer.
Personal
and family history: If you have had lung cancer,
you have a higher risk of getting another lung cancer.
Brothers, sisters, and children of people who have had
lung cancer may have a slightly higher risk themselves.
Diet: Some reports suggest that a diet low in fruits
and vegetables might increase the risk of lung cancer
in people who are exposed to tobacco smoke. It may turn
out that fruits and vegetables help protect against
lung cancer.
Air pollution: In some cities, air pollution may slightly
increase the risk of lung cancer. But the risk is still
far less than that caused by smoking.
During the past few years, scientists have made great
progress in understanding how risk factors produce certain
changes in the DNA of lung cells, causing the cells
to become cancerous. DNA is the genetic material that
carries the instructions for nearly everything our cells
do.
Current research in this field is aimed at developing
tests that can find lung cancers at an early stage by
spotting DNA changes. But these tests are not yet ready
for routine use. Therefore, doctors stress avoiding
tobacco smoke and the other risk factors listed above.
Can Small Cell Lung Cancer
Be Prevented?
The best way to prevent lung cancer is to not smoke
and to avoid people who do. If you already smoke, you
should try to quit. You should also avoid breathing
in other people's smoke.
A good diet with lots of fruits and vegetables may also
help prevent lung cancer.
Some people who get lung cancer do not have any known
risk factors, so it is not possible to prevent all cases
of lung cancer.
How Is
Small Cell Lung Cancer Found?
Since most people with early lung cancer do not have
any symptoms, only a small number of lung cancers are
found at an early stage. When lung cancer is found early,
it is often because of tests that were being done for
something else.
Screening
Tests for Lung Cancer
Screening is the use of tests or exams to find a disease
(such as cancer) in people who don't have any symptoms.
Because lung cancer often spreads beyond the lungs before
it causes symptoms, a good screening test to find lung
cancer early could save many lives.
Chest x-rays and checking sputum (spit) under a microscope
to look for cancer cells have been studied for several
years. Studies have shown that this kind of screening
does not find many lung cancers early enough to improve
a person's chance for a cure. For this reason, lung
cancer screening is not usually advised, even for people
at higher risk, such as those who smoke.
Recently, a new x-ray method called spiral CT scanning
has shown some promise in finding early lung cancer
in smokers and former smokers. But it has not yet known
if this test will lower the chances of dying from lung
cancer. One major problem is that it finds a lot of
things that turn out not to be cancer. This leads to
unnecessary tests and even surgery.
To find out how useful this test might be, a large study
is going on. It is called the National Lung Screening
Trial (NLST). When the results come out, we will have
a better idea whether spiral CT scanning will catch
lung cancer early enough to save lives. Until then,
people who are interested in testing should understand
the pros and cons of this test. And people who smoke
should keep in mind that the best way to avoid dying
from lung cancer is to stop smoking.
Common
Signs and Symptoms of Lung Cancer
Although most lung cancers do not cause symptoms until
they have spread, you should report any of the following
to your doctor right away:
• a cough that
does not go away
• chest pain, often made
worse by deep breathing, coughing, or laughing
• hoarseness
• weight loss and loss of
appetite
• bloody or rust-colored sputum (spit
or phlegm)
• shortness of breath
•
infections such as bronchitis and pneumonia that keep
coming back
• new onset of wheezing
Often these problems are caused by something other than
cancer. But if lung cancer is found, getting treatment
right away could help you live longer and relieve symptoms.
When lung cancer spreads to distant organs, it may cause:
" bone pain
" headache, weakness or numbness
of the arms or legs
" dizziness or seizure
" yellow coloring of the skin and eyes (jaundice)
" lumps near the surface of the body, caused by cancer
spreading to the skin or to lymph nodes in the neck
or above the collarbone
If you have any of these symptoms, you should see a
doctor right away.
Less often, there are some other clusters of symptoms
(called syndromes) that can point to a possible lung
cancer.
If Lung Cancer
Is Suspected
After asking questions about your health and doing a
physical exam, your doctor might want to do some of
the following:
Imaging
Tests
There are a number of different tests that can produce
pictures of the inside of your body. Some of these are
used to find lung cancer and to see if it has spread.
Chest x-ray:
This is the first test your doctor will order to look
for any spot on the lungs. It is a plain x-ray of your
chest. If the x-ray is normal, you most likely do not
have lung cancer. If anything looks suspicious, the
doctor may order more tests.
CT
scan (computed tomography; tuh-mah-gruh-fee):
A CT scan is a special kind of x-ray. Instead of taking
just one picture, the CT scanner takes many pictures
as it moves around you. A computer then combines these
pictures into an image of a slice of your body. Often
after the first set of pictures is taken you will get
an injection of a "dye" that helps to outline structures
in your body. Then a second set of pictures is taken.
CT scans take longer than normal x-rays, but they are
getting faster all the time.
The CT scan will give the doctor exact information about
the size, shape, and place of a tumor. It can also help
find swollen lymph nodes that might contain cancer.
CT scans are also used to find tumors in other organs
that might be affected by the spread of lung cancer.
MRI scan (magnetic resonance
imaging): MRI scans use radio waves and strong
magnets instead of x-rays to make pictures of your insides.
MRI scans take longer than x-rays-often up to an hour.
Also, you have to be placed inside a tube-like machine,
which upsets some people. MRI scans are useful in finding
lung cancer that has spread the brain or spinal cord.
PET scan (positron emission
tomography): PET uses a form of sugar that
contains a radioactive atom. Cancer cells in the body
absorb large amounts of the sugar. A special camera
can then detect the radioactivity. This test can show
whether the cancer has spread to the lymph nodes. It
is also helpful in telling whether a spot on your chest
x-ray is cancer. PET scans are also useful when the
doctor thinks the cancer has spread, but doesn't know
where. Newer machines combine a CT and a PET scan to
even better pinpoint the tumor.
Bone
scan: For a bone scan a small amount of radioactive
substance is injected into a vein. The amount used is
very low and causes no long-term effects. This substance
builds up in areas of bone that may be abnormal because
of cancer. But other problems can also cause suspicious
results. Bone scans are usually done in patients with
small cell lung cancer. They are only done in patients
with non-small cell lung cancer when other tests or
symptoms suggest that the cancer has spread to the bones.
Other Tests
The following tests can be used to confirm whether something
seen on an imaging test is really lung cancer. These
tests are also used to decide the exact type of lung
cancer and how far it may have spread.
Sputum
cytology (sigh-tahl-uh-jee): A sample of phlegm
(spit) is looked at under a microscope to see if cancer
cells are present.
Needle
biopsy: A long, thin needle is placed into
the tumor in the lung to remove a piece of tissue. The
tissue is looked at under the microscope to see if cancer
cells are present.
Bronchoscopy
(bron-kos-kuh-pee): A lighted, flexible tube
is passed through the mouth into the bronchi. This test
can help find tumors or it can be used to take samples
of tissue or fluids to see if cancer cells are present.
You will need to be sedated for this exam.
EUS (endoscopic esophageal
ultrasound): In this test, a flexible scope is placed
through the mouth into the tube that goes to the stomach
(the esophagus). The esophagus is close to some lymph
nodes inside the chest, and lung cancer can spread to
these lymph nodes. Ultrasound images taken from inside
the esophagus can show if these lymph nodes are swollen.
If they are, a thin needle can be used to take a sample
of these nodes to see if cancer cells are present.
Thoracentesis (thor-uh-sen-tee-sis)
and thoracoscopy (thor-uh-kos-kuh-pee): These tests
are done to check whether fluid around the lungs is
caused by cancer or by a condition such as heart failure
or an infection. For thoracentesis, the skin is numbed
and a needle is placed between the ribs to drain the
fluid. This fluid is checked for cancer cells. Thoracoscopy
uses a thin, lighted tube connected to a video camera
and monitor to look at the space between the lungs and
the chest wall. You will need to be sedated for these
tests.
Bone marrow biopsy:
After the area is numbed, a needle is used to remove
a small piece of bone, usually from the back of the
hip bone. The sample is checked for cancer cells. This
is done mostly to help find if small cell lung cancer
has spread to the bones.
Blood
tests: A complete blood count (CBC) shows whether
your blood has the correct number of different cell
types. This test will be done often if you are treated
with chemotherapy because these drugs can affect the
blood-forming cells of the bone marrow. Other blood
tests can spot problems in different organs, such as
the liver and bones.
How
Is Small Cell Lung Cancer Treated?
If you have small cell lung cancer, the main treatment
will be chemotherapy, either alone or combined with
radiation. Very rarely, surgery might be done, depending
on the stage of the cancer.
After the cancer is found and staged, your doctor will
talk to you about treatment choices. Give yourself time
to take in the information you have learned. The most
important factors to take into account include the stage
and type of cancer, your overall health, the likely
side effects of the treatment, and the chance of curing
the cancer or extending your life. Age alone should
not prevent treatment. Older people can benefit from
treatment as much as younger people as long as their
general health is good.
It is often a good idea to get a second opinion. A second
opinion can provide more information and help you feel
good about the treatment plan you choose.
Types of Treatment for Small Cell
Lung Cancer
Surgery
Surgery is rarely used in small cell lung cancer. In
about 1 out of 20 cases, the small cell lung cancer
is in only one tumor nodule, with no spread to lymph
nodes or other organs. In these cases, surgery might
be helpful and it is usually followed by further treatment
with chemotherapy or radiation.
Removing only part of a lobe (section) of the lung is
called a wedge resection. If a whole lobe of the lung
is removed, the surgery is called a lobectomy (low-bek-tuh-me).
If the entire lung is removed, the surgery is called
a pneumonectomy (new-mo-NECK-tuh-me).
These operations are done with the patient asleep. A
hospital stay of 1 or 2 weeks is usually needed. There
will be some pain after the surgery because the surgeon
has to cut through the ribs to get to the lungs. Other
possible problems include bleeding, wound infections,
and pneumonia.
There is a new kind of surgery for people with early
stage lung cancer. It is called video-assisted chest
surgery. A tiny camera can be placed through a small
hole in the chest to help the surgeon see the tumor.
Only small incisions are needed, so there is less pain
after surgery. This approach is most often used for
tumors smaller than about 2 inches. The cure rate seems
to be the same as for standard surgery. The doctor who
does this surgery should have experience since it requires
a lot of skill.
People whose lungs are in good condition (other than
the cancer) can often return to normal activities after
a lobe or even an entire lung is removed. But if they
also have problems such as emphysema or chronic bronchitis
(common in heavy smokers), they may have long-term shortness
of breath.
For people who can't have the usual surgery because
of lung disease, other medical problems, or because
the cancer is widespread, other types of surgery (for
example, laser surgery) can be done to relieve symptoms.
Sometimes fluid collects in the chest and interferes
with breathing. This fluid can be removed through a
small tube placed in the chest. After the fluid is drained
out either talc or some type of drug is placed into
the chest. This will start a reaction that will help
seal the space and prevent future fluid buildup..
Radiation Therapy
Radiation therapy is treatment with high-energy rays
(such as x-rays) to kill or shrink cancer cells. The
radiation comes from outside the body (external radiation).
In small cell lung cancer it is most often used along
with chemotherapy (in limited stage disease) to treat
the tumor and lymph nodes in the chest.
Radiation might be used after surgery to kill small
areas of cancer that can't be seen and removed during
surgery. Or it could be used on the brain to try to
prevent the spread of cancer there. Radiation can also
be used to relieve symptoms such as pain, bleeding,
trouble swallowing, or problems caused by the cancer
spreading to the brain.
Side effects of radiation could include mild skin problems,
nausea, vomiting, and tiredness. Often these go away
after a short while. Chest radiation may cause lung
damage and trouble breathing or swallowing.
Side effects of radiation therapy to the brain usually
become most serious 1 or 2 years after treatment. These
side effects could include memory loss, headaches, trouble
with thinking, and less sexual desire. These side effects,
though, are minor compared to those caused by a brain
tumor.
A special kind of radiation (called the gamma knife)
can be used instead of surgery if the cancer spreads
to only 1 spot in the brain. In this method, several
beams of radiation are focused on the tumor over the
span of a few minutes to hours. The head is held in
place with a rigid frame while this is done.
Chemotherapy
Chemotherapy is treatment with anticancer drugs given
into a vein or by mouth. These drugs enter the bloodstream
and reach throughout the body, making this treatment
useful for cancer that has spread (metastasized) to
organs beyond the lung. Chemotherapy is usually the
main treatment for small cell lung cancer. Several drugs
may be given at the same time
Chemotherapy drugs kill cancer cells but they also damage
some normal cells, causing side effects. These side
effects depend on the type of drugs used, the amount
given, and the length of treatment. You could have some
of these short-term side effects:
• nausea
and vomiting • loss of appetite • hair loss
(temporary) • mouth sores • loose stools (diarrhea)
• a higher risk of infection caused by a shortage
of white blood cells • bruising or bleeding after
minor cuts caused by a shortage of blood platelets •
fatigue or shortness of breath caused by low red blood
cell counts (anemia)
Some chemotherapy drugs can damage nerves. This can
cause numbness in the fingers and toes, and sometimes
the arms and legs may feel weak.
Most of these side effects go away when treatment is
over. Be sure to tell your doctor or nurse if you have
any side effects, as there are often ways to help.
Small Cell Lung Cancer Survival
by Stage
If small cell lung cancer is found very early and seems
to only be in the lung, the relative 5-year survival
rate is around 21%. But very few patients fall into
this group. If the cancer has shown any signs of spread,
the relative 5-year survival rate is around 11%. For
people with extensive disease, the rate drops to 2%.
These descriptions, though, depend on how hard the doctors
look for spread.
Five-year relative survival rates means that people
who die of other causes are not included, and the rate
only includes people who die from lung cancer.
While these numbers provide an overall picture, keep
in mind that every person's situation is unique and
the statistics can't predict exactly what will happen
in your case. Talk with your cancer care team if you
have questions about your own chances of a cure, or
how long you might survive your cancer. They know your
situation best.
Clinical
Trials
Studies of promising new treatments are known as clinical
trials. A clinical trial is done only when there is
some reason to believe that the new treatment may be
of value to the patient. Clinical trials are needed
in order to find new and better ways to treat cancer.
Treatments used in clinical trials are often found to
have real benefits. The main questions the researchers
want to answer are:
• Is this treatment
helpful?
• Does it work better than the one
we're now using?
• What side effects does
it cause?
• Do the benefits outweigh the side
effects?
• Which patients are most likely
to find this treatment helpful?
Clinical trials are carried out in steps called phases.
Each phase is designed to answer certain questions.
Phase I clinical
trials look at the best way to give a new treatment
and how much of it can be given safely. The main purpose
of a phase I study is to test the safety of the new
drug.
Phase II
clinical trials are designed to see if the drug works.
Patients are given the highest dose that doesn't cause
serious side effects and then watched closely to see
if there is an effect on the cancer.
Phase
III clinical trials compare the new treatment
with standard treatment. Large numbers of patients are
divided into 2 groups. The control group receives standard
treatment and the other group receives the new treatment.
Everyone is closely watched to see which treatment is
more effective. The study is stopped if the side effects
are too severe or if one group has much better results
than the other.
If you are in a clinical trial, you will have a team
of experts watching your progress very carefully. However,
there are some risks. No one knows in advance if the
treatment will work or exactly what side effects will
occur. That is what the study is designed to discover.
Keep in mind, though, that even standard treatments
have side effects.
Taking part in a clinical trial is completely up to
you. Even after joining a clinical trial, you are free
to leave the study at any time, for any reason. Taking
part in the study will not prevent you from getting
other medical care you may need.
Courtesy:
www.cancer.org,
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