Overview, Causes, & Risk Factors
Primary
lung cancer is a very serious respiratory disorder that begins in the airways and air sacs of the lungs.
What is going on in the body?
cancer of the
lung can begin in the lining of the trachea, the smaller airways, and the tiny air sacs. There are different types of
lung cancer. Non-small cell
lung cancer, or NSCLC, accounts for 70% to 80% of
lung cancers. Small cell
lung cancer or oat cell carcinoma, or SCLC, accounts for 25% of
lung cancers. Both types can be fatal. They invade surrounding tissue and can spread to other parts of the body through the lymph nodes and bloodstream.
lung cancer is the most common and most deadly
cancer in the US. Roughly 160,000 deaths occur each year. Men and woman are equally affected. Most types of
lung cancer are aggressive, spreading early in their course.
lung cancer can cause life threatening complications in the chest and spread to distant sites throughout the body causing death in this way. A person also may have symptoms which are reactions to tumors or a substance they make, called a paraneoplastic syndrome.
What are the causes and risks of the disease?
Inhaling tobacco smoke probably causes at least 90% of all
lung cancer. Smokers have more than 30 times the risk of nonsmokers. A person's risk for
lung cancer depends on how many packs of cigarettes he or she smokes each day and for how many years. People who quit smoking remain at risk, sometimes for decades. People exposed to radiation, radon, asbestos, and probably heavy l are also at risk.
lung cancer occurs if the cells lining the airways of the lungs are constantly exposed and stimulated by cancer-causing substances over several decades. This changes the genetic DNA, makeup of cells and results in the uncontrollable growth of abnormal cells.
It is very rare for a person who has not been exposed to cigarette smoke or radiation to develop small cell
lung cancer. It occurs most often in middle aged and elderly people who have been exposed to cancer-causing poisons for several decades.
Symptoms & Signs
What are the signs and symptoms of the disease?
Symptoms of
lung cancer include:
a cough
blood-tinged spit
shortness of breath
dull, achy chest pain
sharp chest pain that gets worse when the person moves
hoarseness
trouble swallowing
A person with this disease may also have:
fever
loss of appetite
weight loss
muscle loss
fatigue
Sometimes the disease has spread by the time it is diagnosed. If so, symptoms can include:
headache
blurred vision
seizures
strokes
slurred speech
neurologic problems
People often come to the healthcare provider with symptoms of bone pain, pneumonia, enlarged, hard, mostly painless lymph nodes, an enlarged liver and jaundice. Listening to the heart, the doctor may find dullness, loss of breath sounds, a pleuritic rub or a sound caused by an irritated
lung lining, and wheezing. The person's skin may be bluish, and the tips of his or her fingers may be abnormally enlarged.
lung cancer also can cause many serious problems ranging from paralysis to heart failure.
Diagnosis & Tests
How is the disease diagnosed?
The disease is diagnosed by taking a tissue sample of the lung. There are many ways to collect a tissue sample. Biopsies are obtained wherever the
cancer is most accessible. Needle puncture, brush or pinch biopsy is frequently all that is needed. Various ways to collect tissue include:
needle aspiration of pleural fluid through the chest wall
pleural biopsy
mediastinoscopy
bronchoscopy
needle biopsy of a liver mass
biopsy of tissue from a peripheral lymph node obtained either through needle biopsy or a surgical incision
biopsy of a mass in any of the body
Through this tissue sample, doctors can tell if the
cancer is small cell or non-small cell. Small cell is an aggressive
lung cancer deriving from the neuroendocrine cells. It usually has spread
cancer cells throughout the body at the time of diagnosis. Frequently a bone marrow biopsy is performed to see if it has spread to the bones. Sing for small cell
lung cancer is generally divided into limited disease versus extensive disease.
Non-small cell
lung cancer can include all kinds of different cells. Some are flat and scaly, while other disguise themselves as
lung cells. These cancers are categorized or sed differently than small cell because this type of
lung cancer may be curable. In order to evaluate whether removing all or part of the
lung may be feasible, more tests are needed. This includes blood tests, MRI scan of the chest, and bronchoscopy. Other tests, including a bone scan, liver scan or CT scan, may also be needed.
Diagnostic sing is somewhat complex.
Se I consists of a
lung mass that has not invaded the chest wall, trachea, or lymph nodes.
Se II can involve the lymph nodes in the area where the windpipe branches into the two lungs, but not the center of the chest around the heart.
Se III consists of involvement of lymph nodes in the hilum, which is an area at the root of the lungs (III-A), or a locally invasive tumor (III-B).
Se IV involves any tumor in the
lung that has spread outside of the chest.
At many times exact sing is not known until the chest is opened for surgery.
Prevention & Expectations
What can be done to prevent the disease?
This best way to prevent this
cancer is not to smoke and to avoid exposure to second-hand smoke. People who want to quit smoking can try:
behavior modification programs
support groups
nicotine chewing gum
nicotine patches
bupropion medication
alternative approaches such as biofeedback, hypnosis, and acupuncture
Educating young people about the dangers of smoking is a key preventive strategy.
Radon is a cancer-causing substance that should also be avoided. It is sometimes found in the home. If present, it can be reduced to acceptable levels by various means, such as caulking and creating more ventilation.
Early diagnosis may help in reducing some deaths, however,
lung cancer tends to spread early. There are no reliable screening blood tests or sputum tests, and screening chest X-rays have not been shown to be cost effective on a population-wide basis.
What are the long-term effects of the disease?
Se I cancers are considered curable by surgical removal 50 to 90% of the time.
Se II are curable, but less than 50% of the time. Curability drops off rapidly in later se disease.
People with se III-B and IV have an average survival of less than 1 year.
Small cell
lung cancer with bulky static disease has a survival of less than 1 year as well. Some patients with grossly limited small cell
lung cancer can survive for more than 2 years with aggressive treatment with combination chemotherapy and radiation therapy.
What are the risks to others?
Others are not put at risk since this type of
cancer is not considered conious. People who continue to smoke expose others to the toxic substances in second hand smoke. Radon is a risk factor for any type of
lung cancer. Asbestos has been linked to some non-small cell
lung cancers.
Treatment & Monitoring
What are the treatments for the disease?
Small cell
lung cancer spreads throughout the body. It is sensitive to chemotherapy and radiation therapy. Surgery to remove the
cancer where it started is usually not helpful. Multiple agent chemotherapy is given with limited or extensive small cell
lung cancer. Response rates are good and some complete remissions are attainable. Chemotherapy is often followed or sandwiched with radiation therapy to the
Primary cancer site. Radiation to the brain has been used with small cell
lung cancer because this is where it often spreads, even after treatment has been finished. Chemotherapy drugs that are used include etoposide, cisplatin, carboplatin, doxorubicin, vincristine, and cyclophosphamide.
Limited se non-small cell, such as se I and II cancer, are considered curable. Treatment includes the partial removal of the
lung and the removal of lymph nodes in the chest cavity. This is followed up with radiation therapy. Chemotherapy in addition to the radiation may or may not be helpful. Pre- or postoperative chemotherapy have been given along with complete surgical removal. People with higher ses of
cancer are not likely to benefit from extensive surgery. They are treated with radiation and/or chemotherapy to relieve symptoms and make them comfortable. Radiation therapy can be given from the outside of the body or through the windpipe. Chemotherapy drugs that have given response include vinblastine, vincristine, cisplatin, etoposide, and 5-fluorouracil (5-FU).
People who's
cancer has spread to the brain may benefit from whole brain irradiation and corticosteroids to reduce brain swelling. Radiation and/or chemotherapy may relieve other symtoms including painful enlarged liver, bone pain caused by stases from the
lung cancer, or general failing health.
Fluid in the chest containing cancerous cells is treated with needle or chest tube drainage followed by instillation of chemotherapy into the space within the chest that holds the lungs. This will dry up any fluid and improve symptoms. Normal
lung is very sensitive to radiation damage, so a complete
lung cannot be exposed to radiation. Experimental therapies are desirable for treatment of all ses of this disease since it has been so common and highly lethal. Additional information will benefit the hundreds of thousands of people who have yet to develop this disease. People with this disease often suffer from too much calcium in the blood. It is treated with corticosteroids, diphosphonate medicine, or
Primary treatment of the cancer.
A team of medical experts is often needed to manage
lung cancer. This includes thoracic surgeons, radiation therapists,
cancer specialists,
lung specialists, and radiologists. Experimental treatments are available at many local, regional, or national institutions. New drugs are being developed and tried in people who have incurable
lung cancer. Terminal care can be provided by a hospice-d team.
What are the side effects of the treatments?
When surgery is done to remove part of a lung, it can result in the
lung not being able to work. Before surgery, it is important to test the uninvolved
lung to see if this can be tolerated. Opening the chest cavity is major surgery, and can have significant illness and even death associated with it.
Side effects of radiation include:
skin burn
redness, swelling, and pain in the lining of the esophagus, a condition called esophagitis
injuring the lungs
fatigue
nausea
Chemotherapy also has many side effects. The drugs that are used will cause:
hair loss
nausea
vomiting
lowered blood counts and risks of infections
potential need for transfusions
abnormal bleeding or blood clotting
damage to nerves, kidneys, and liver
People who receive radiation to the brain can have:
problems with short-term memory losses
difficulty walking
coordination problems
loss of brain cells
Some people may need daily oxygen even if they didn't before treatment. This disease can recur in spite of all of the above treatments.
What happens after treatment for the disease?
After treatment, people will be followed for
lung function, any delayed or prolonged side effects of the treatments, and for recurrence of the disease.
How is the disease monitored?
Monitoring is by frequent visits to the healthcare provider. Physical exams, laboratory tests, chest CT, abdominal CT, and sometimes bronchoscopy are needed. The
cancer may return within several months to a few years. People with
lung cancer usually have a history of smoking. They remain at risk for development of other tumors, including another
lung cancer primary.
Attribution
Author:Thomas Fisher, MD
Date Written:
Editor:Smith, Elizabeth, BA
Edit Date:05/25/00
Reviewer:Fern Carness, RN, MPH
Date Reviewed:04/11/01