LUNG CANCER
What causes lung cancer?
- Cigarettes - Smoking cigarettes can cause lung cancer. This is most often small-cell cancer or squamous cell carcinoma. Harmful substances, called carcinogens, in tobacco damage the cells in the lungs. Over time, the damaged cells may become cancerous. The likelihood that a smoker will develop lung cancer is affected by the age at which smoking began, how long the person has smoked, the number of cigarettes smoked per day, and how deeply the smoker inhales. Stopping smoking greatly reduces a person's risk for developing lung cancer.
- Cigars and Pipes - Cigar and pipe smokers have a higher risk of lung cancer than nonsmokers. Even cigar and pipe smokers who do not inhale are at increased risk for lung, mouth, and other types of cancer.
- Environmental Tobacco Smoke - The chance of developing lung cancer is increased by exposure to environmental tobacco smoke (ETS) -- the smoke in the air when someone else smokes. Exposure to ETS, or secondhand smoke, is called involuntary or passive smoking.
- Radon - Radon is an invisible, odorless, and tasteless radioactive gas that occurs naturally in soil and rocks. It can cause damage to the lungs that may lead to lung cancer. People who work in mines may be exposed to radon and, in some parts of the country, radon is found in houses.
- Asbestos - Asbestos is the name of a group of minerals that occur naturally as fibers and are used in certain industries. Asbestos fibers tend to break easily into particles that can float in the air and stick to clothes. When the particles are inhaled, they can lodge in the lungs, damaging cells and increasing the risk for lung cancer.
- Pollution - Researchers have found a link between lung cancer and exposure to certain air pollutants, such as by-products of the combustion of diesel and other fossil fuels. However, this relationship has not been clearly defined, and more research is being done.
- Lung Diseases - Certain lung diseases, such as tuberculosis (TB) and mesothelioma increase a person's chance of developing lung cancer. Lung cancer tends to develop in areas of the lung that are scarred from TB.
- Personal History - A person who has had lung cancer once is more likely to develop a second lung cancer compared with a person who has never had lung cancer. Quitting smoking after lung cancer is diagnosed may prevent the development of a second lung cancer.
Types of lung cancer
There are two main types of lung cancer:- Small cell lung cancer (SCLC) - About 20% of all lung cancers are of the small cell type. 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.
- Non-small cell lung cancer (NSCLC) - About 80% of lung cancers are of the non-small cell type. There are 3 sub-types within this group:
- Squamous cell carcinoma - usually linked to a history of smoking.
- Adenocarcinoma - usually found in the outer region of the lung.
- Large-cell undifferentiated carcinoma - can appear in any part of the lung and tends to grow and spread quickly, resulting in a poor outlook for the patient.
What are the Symptoms of Lung Cancer?
- A cough that doesn't go away and gets worse over time
- Constant chest pain
- Coughing up blood
- Shortness of breath, wheezing, or hoarseness
- Repeated problems with pneumonia or bronchitis
- Swelling of the neck and face
- Loss of appetite or weight loss
- Fatigue
How is Lung Cancer Diagnosed?
To help find the cause of symptoms, the doctor evaluates a person's medical history, smoking history, exposure to environmental and occupational substances, and family history of cancer. The doctor also performs a physical exam and may order a chest x-ray and other tests. If lung cancer is suspected, sputum cytology (the microscopic examination of cells obtained from a deep-cough sample of mucus in the lungs) is a simple test that may be useful in detecting lung cancer. To confirm the presence of lung cancer, the doctor must examine tissue from the lung. A biopsy -- the removal of a small sample of tissue for examination under a microscope by a pathologist -- can show whether a person has cancer.
If the diagnosis is cancer, the doctor will want to learn the stage (or extent) of the disease. Staging is done to find out whether the cancer has spread and, if so, to what parts of the body. Lung cancer often spreads to the brain or bones. Knowing the stage of the disease helps the doctor plan treatment. Some tests used to determine whether the cancer has spread including CAT scan, MRI, bone scan, radionuclide scan.
What is the Treatment for Lung Cancer?
Treatment depends on a number of factors, including the type of lung cancer (non-small or small cell lung cancer), the size, location, and extent of the tumor, and the general health of the patient. Many different treatments and combinations of treatments may be used to control lung cancer, and/or to improve quality of life by reducing symptoms. These treatments can include surgery, chemotherapy, photodynamic therapy, and/or radiation.
Clinical trials (research studies) to evaluate new ways to treat cancer are an option for many lung cancer patients.
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