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| Cancer Information > Types
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More than 90,000 men and 79,000 women are diagnosed
each year with cancer of the lungs and bronchi (the air tubes
leading to the lungs). Among men, the incidence of lung cancer
has been declining, but it continues to increase among women.
The number of lung cancer deaths among women surpasses those
from breast cancer.
Recent studies indicate that female smokers may
be more likely to develop lung cancer than male smokers.
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There are two major types of primary lung cancer:
non-small cell and small cell. Each affects different types
of cells in the lung and grow and spread in different ways,
so doctors treat them differently. A diagnosis will include
not only the type of lung cancer but the stage, which describes
the extent and spread of the disease at diagnosis.
- Non-Small Cell Lung Cancer
Non-small cell lung cancer, the most common type of lung
cancer, is usually associated with a history of smoking.
The three main types of non-small cell lung cancer are named
for the type of cell found in the tumor: squamous cell carcinoma
(also called epidermoid carcinoma); adenocarcinoma; and
large cell carcinoma. Non-small cell lung cancer is described
using four stages: in stage I, the cancer is confined to
the lung; in stages II and III, the cancer is confined to
the chest; and in stage IV, the cancer has spread from the
chest.
- Small Cell Lung Cancer
Small cell lung cancer (sometimes called oat cell lung cancer)
accounts for approximately 20 percent of all lung cancer
cases and is also associated with a history of smoking.
The extent of the disease is described using a two-stage
system. A case can either be limited, meaning the cancer
is confined to a portion of the chest where it originated,
or extensive, meaning the cancer has spread throughout or
from the chest.
Mesothelioma, a rare cancer of the chest and
abdominal lining, primarily affects persons who have had occupational
exposure to asbestos particles.
Tumors found in the lungs sometimes originate
from cancers elsewhere in the body. These tumors are called
lung metastases.
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Smoking tobacco in any form is the major
risk factor for lung cancer. Nonsmokers who breathe the smoke
of others, often called secondhand smoke, are also at increased
risk for lung cancer. Stopping exposure to tobacco smoke at
any age lowers the risk of lung cancer.
Risk factors for lung cancer besides smoking
include the following:
- Radon
An odourless radioactive gas produced naturally in rocks
and soil, radon is found in homes and mines in some areas.
Exposure to high indoor radon levels can cause damage to
the lungs that may lead to cancer.
- Asbestos
If inhaled, asbestos particles can cause lung damage that
may lead to lung cancer and mesothelioma (a rare cancer
of the chest and abdominal lining).
Smoking Cessation
Not everyone who gets lung cancer has a history
of smoking. If you do smoke, however, you can reduce your
risk for lung cancer -- and the risk of those around you --
by stopping now.
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Lung cancer is difficult to detect early because
symptoms usually do not appear until the disease is advanced.
Symptoms depend on the location of the tumor and can include
persistent cough, hoarseness or wheezing, shortness of breath,
sputum streaked with blood, recurring bronchitis or pneumonia,
weight loss and loss of appetite, and chest pain.
Physicians use several techniques to diagnose
lung cancer, including the following:
Imaging Tests
Chest x-rays, computed tomography (CT) scans,
and magnetic resonance imaging (MRI) help locate abnormal
areas in the lung.
Low-Dose Helical CT
A technique called low-dose helical (or spiral)
CT may offer a novel approach for diagnosing lung cancer by
exposing the patient to less radiation than a conventional
chest CT scan while allowing the doctor to see areas of the
chest normally obscured in a standard x-ray.
Bronchoscopy & Biopsies
A sputum sample can be analyzed for the presence
of cancerous cells. Doctors may perform a bronchoscopy, which
allows them to examine the bronchial passages using an instrument
called a bronchoscope. This is a small tube that is inserted
through the nose or mouth, down the throat and into the bronchi.
During the procedure physicians may remove some tissue for
analysis.
A modified form of bronchoscopy called autofluorescence
bronchoscopy, which can detect early invasive cancers not
seen with standard x-rays or white-light bronchoscopy, is
being used to detect very early lung cancer.
To examine areas of the lungs that are not accessible
during a bronchoscopy, physicians may perform a needle biopsy
("fine needle aspiration" or FNA) to remove a small sample
of tissue for analysis.
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Depending on the type and stage of the disease,
lung cancer can be treated with surgery, chemotherapy, radiation
therapy, or a combination of these treatments.
Surgery
For non-small cell lung cancers that have not
spread beyond the lung, surgery is most often used. Over the
past several years, surgical techniques for treating lung
cancer have improved greatly.
There are three surgical procedures commonly
used to treat lung cancer:
- wedge resection, or segmentectomy (in which
a small section of the lung is removed)
- lobectomy (in which an entire section is removed)
- pneumonectomy (which involves the removal
of an entire lung)
Minimally Invasive Surgery
Where appropriate, we offer minimally invasive
surgical procedures, including video-assisted thoracic surgery
(VATS), or thoracoscopy. VATS allows the surgeon to operate
with roboting assistance by inserting an illuminated tube
through a small incision into the lung through the ribs. Because
the incisions are much smaller than with an open operation,
post-operative healing time and pain are reduced.
Chemotherapy
For patients whose tumors are somewhat more advanced,
a program of chemotherapy before surgery increases the cure
rate. In some cases, the cancer is completely eliminated with
chemotherapy before the patient has even had surgery.
Even if the surgeon removes the entire tumor
that can be seen, adjuvant chemotherapy may be offered to
kill cancer cells that may still be present in nearby tissues
or elsewhere in the body. For small cell lung cancer in particular,
chemotherapy, often combined with radiation therapy, is now
the most common treatment.
Radiation Therapy
When surgery is not the best option, our radiation
therapy system permits the delivery of the highest possible
radiation dose targeted precisely to the tumor. This method
spares normal tissues and lessens damage to other organs in
the chest. Radiation therapy is also sometimes used to relieve
pain and bleeding and alleviate problems with swallowing.
Both 3-D conformal radiation therapy and intensity
modulated radiation therapy (IMRT) allow doctors to change
the shape and intensity of radiation beams so they are focused
more effectively on cancer cells and away from the surrounding
tissue and organs.
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