Identification of an ALK gene rearrangement in a lung cancer is important for deciding the optimal treatment course. The ALK rearrangement means that drugs that specifically act against the abnormal fusion protein can be used. Three drugs, crizotinib Xalkoriceritinib Zykadiaand alectinib Alecensahave been developed to target the activity of the abnormal fusion protein, and additional agents are under development.
Ceritinib or alectinib is typically given if the cancer becomes resistant to crizotinib or if the patient is unable to tolerate crizotinib. Normally, the body maintains a system of checks and balances on cell growth so that cells divide to produce new cells only when new cells are needed.
Disruption of this system of checks and balances on cell growth results in an uncontrolled division and proliferation of cells that eventually forms a mass known as massage therapy and cancer tumor.
Tumors can be benign or malignant ; when we speak of "cancer," we are referring to those tumors that are malignant. Benign tumors usually can be removed and do not spread to other parts of the body. Malignant tumors, on the other hand, often grow aggressively locally where they start, but tumor cells also can enter into the bloodstream or lymphatic system and then spread to other sites in the body.
This process of spread is termed metastasis ; the areas of tumor growth at these distant sites are called metastases. Since lung cancer tends to spread or metastasize very early after it forms, it is a very life-threatening cancer and one of the most difficult cancers to treat. While lung cancer can spread to any organ in the body, certain locations -- particularly the adrenal glands, liverbrain, and bones -- are the most common sites for lung cancer metastasis.
The lung also is a very common site for metastasis from malignant tumors in other parts of the body. Tumor metastases are made up of the same types of cells as the original primary tumor. For example, lung cancer signs and symptoms, if prostate cancer spreads via the bloodstream to the lungs, it is metastatic prostate cancer in the lung and is not lung cancer. The principal function of the lungs is to exchange gases between the air we breathe and the blood.
Through the lung, carbon dioxide is removed from the bloodstream and oxygen enters the bloodstream. The right lung has three lobes, while the left lung is divided into two lobes and a small structure called the lingula that is the equivalent of the middle lobe on the right. The major airways entering the lungs are the bronchi, which arise from the trachea, which is outside the lungs.
The bronchi branch into progressively smaller airways called bronchioles that end in tiny sacs known as alveoli where gas exchange occurs.
The lungs and chest wall are covered with a thin layer of tissue called the pleura. Carcinoma is another term for cancer. Cancers also can arise from the pleura called mesotheliomas or rarely from supporting tissues within the lungs, for example, the blood vessels. Lung cancer is the most common cause of death due to cancer in both men and women throughout the world. Statistics from the American Cancer Society estimated that in there will be aboutnew cases of lung cancer in the U.
According to the U. National Cancer Institute, approximately 6. The median age at diagnosis is 70 years. Lung cancer was not common prior to the s but increased dramatically over the following decades as tobacco lung cancer signs and symptoms increased. In many developing countries, the incidence of lung cancer is beginning to fall following public education about the dangers of cigarette smoking and the introduction of effective smoking -cessation programs.
Nevertheless, lung cancer remains among the most common types of cancers in both men and women worldwide. The risk of lung cancer increases with the number of lung cancer signs and symptoms smoked and the time over which smoking has occurred; doctors refer to this risk in terms of pack-years of smoking history the number of packs of cigarettes smoked per day multiplied by the number of years smoked.
For example, a person who has smoked two packs of cigarettes per day for 10 years has a 20 pack-year smoking history, lung cancer signs and symptoms. While the risk of lung cancer is increased with even a pack-year smoking history, those with pack-year histories or more are considered to have the greatest risk for the development of lung cancer. Among those who smoke two or more packs of cigarettes per day, one in seven will die of lung cancer.
Pipe and cigar smoking also can cause lung cancer, although the risk is not as high as with cigarette smoking.
Thus, while someone who smokes one pack of cigarettes per day has a risk for the development of lung cancer that is 25 times higher than a nonsmoker, pipe and cigar smokers have a risk of lung cancer that is about five times that of a nonsmoker. Tobacco smoke contains over 4, chemical compounds, many of which have been shown to be cancer-causing or carcinogenic.
The two primary carcinogens in tobacco smoke are chemicals known as nitrosamines and polycyclic aromatic hydrocarbons. The risk of developing lung cancer decreases each year following smoking cessation as normal cells grow and replace damaged cells in the lung. In former smokers, the risk of developing lung cancer begins to approach that of a nonsmoker about 15 years after cessation of smoking. Passive smoking or the inhalation of tobacco smoke by nonsmokers who share living or working quarters with smokers, also is an established risk factor for the development of lung cancer.
The risk appears to increase with the degree of exposure number of years exposed and number of cigarettes smoked by the household partner to secondhand smoke.
It is estimated that over 7, lung cancer deaths occur each year in the U. Asbestos fibers are silicate fibers that can persist for a lifetime in lung tissue following exposure to asbestos, lung cancer signs and symptoms.
The workplace was a common source of exposure to asbestos fibers, as asbestos was widely used in the past as both thermal and acoustic insulation. Today, asbestos use is limited or banned in many countries, including the U. Both lung cancer and mesothelioma cancer of the pleura of the lung as well as of the lining of the abdominal cavity called the peritoneum are associated with exposure to asbestos, lung cancer signs and symptoms.
Cigarette smoking drastically increases the chance of developing an asbestos-related lung cancer in workers exposed to asbestos; asbestos workers who do not smoke have a fivefold greater risk of developing lung cancer than lung cancer signs and symptoms, but asbestos workers who smoke have a risk that is fifty- to ninety-fold greater than nonsmokers. Radon gas is a natural radioactive gas that is a natural decay product of uranium that emits a type of ionizing radiation.
As with asbestos exposure, concomitant smoking greatly increases the risk of lung cancer with radon exposure, lung cancer signs and symptoms. Radon gas can travel up through soil and enter homes through gaps in the foundation, pipes, lung cancer signs and symptoms, drains, or other openings.
Environmental Protection Agency estimates that one out of every 15 homes in the U. Radon gas is invisible and odorless, but it can be detected with simple test kits. While the majority of lung cancers are associated with tobacco smoking, the fact that not all smokers eventually develop lung cancer suggests that other factors, such as individual genetic susceptibility, may play a role in the causation of lung cancer. Numerous studies have shown that lung cancer is more likely to occur lung cancer signs and symptoms both smoking and nonsmoking relatives of those who have had lung cancer than in lung cancer signs and symptoms general population.
It is unclear how much of this risk is due to shared environmental factors like a smoking household and how much is related to genetic risk. People who inherit certain genes, like genes that interfere with DNA repair, may be at greater risk for several types of cancer. Tests to identify people at increased genetic risk of lung cancer are not yet available for routine use. The presence of certain diseases of the lung, notably chronic obstructive pulmonary disease COPDlung cancer signs and symptoms, is associated with an increased risk four- to six-fold the risk of a nonsmoker for the development of lung cancer even after the effects of concomitant cigarette smoking are excluded.
Pulmonary fibrosis scarring of the lung appears to increase the risk about seven-fold, and this risk does not appear to be related to smoking, lung cancer signs and symptoms.
Survivors of lung cancer have a greater risk of developing a second lung cancer than the general population has of developing a first lung cancer. Air pollution from vehicles, industry, and power plants can raise the likelihood of developing lung cancer in exposed individuals.
Exhaust from diesel engines is made up of gases and soot particulate matter. Many occupations, such as truck drivers, toll booth workers, forklift and other heavy machinery operators, railroad and dock workers, miners, garage workers and mechanics, lung cancer signs and symptoms, and some farm workers are frequently exposed to diesel exhaust. Studies lung cancer signs and symptoms workers exposed to diesel exhaust have shown a small but significant increase in the risk of developing lung cancer.
Lung cancers, also known as bronchogenic carcinomas because they arise from the bronchi within the lungs, are broadly classified into two types: This classification is based upon the microscopic appearance of the tumor cells themselves, specifically the size of the cells. These two types of cancers grow and spread in different ways and may have different treatment options, so a distinction between these two types is important.
SCLC metastasize rapidly to many sites within the body and are most often discovered after they have spread extensively. Referring to a specific cell appearance often seen when examining samples of SCLC under the microscope, these cancers are sometimes called oat cell carcinomas. NSCLC can be divided into several main types that are named based upon the type of cells found in the tumor:. As discussed previously, metastatic cancers from other primary tumors in the body are often found in the lung.
Tumors lung cancer signs and symptoms anywhere in the body may spread to the lungs either through the bloodstream, through the lymphatic system, or directly from nearby organs. Metastatic tumors are most often multiple, scattered throughout the lung, and concentrated in the peripheral rather than central areas of the lung.
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Warning signs of lung cancer are not always present or easy to identify. Lung cancer may not cause pain or other symptoms in some cases. A person with lung cancer may have the following kinds of symptoms:. One should consult a health care professional if he or she develops the symptoms associated with lung cancer, in particular, if they have. The treatment of lung cancer requires a team approach.
Surgical oncologists are surgeons specialized in the removal of cancers. Thoracic surgeons or general surgeons may also surgically treat lung cancers. Medical and radiation oncologists are specialists in the treatment of cancers with medications and radiation therapy, respectively.
Other specialists who may be involved in the care of people with lung cancer include pain and palliative care specialists, as well as pulmonary specialists medical pulmonologists. Doctors use a wide range of diagnostic procedures and tests to diagnose lung cancer. These include the following:. The stage of a cancer is a measure of the extent to which a cancer has spread in the body, lung cancer signs and symptoms. Staging is important for determining how a particular cancer should be treated, since lung cancer therapies are geared toward specific stages.
Staging of a cancer also is critical in estimating the prognosis of a given patient, with higher-stage cancers generally having a worse prognosis than lower-stage cancers. Abnormal blood chemistry tests may signal the presence of metastases in bone or liver, and radiological procedures can document the size of a cancer as well as its spread.
Treatment for lung cancer primarily lung cancer signs and symptoms surgical removal of the cancer, chemotherapy, or radiation therapy, as well as combinations of these treatments. Targeted therapies and immunotherapy are becoming more common, as well. The decision about which treatments will be appropriate for a given individual must take into account the location and extent of the tumor, as well as the overall health status of the patient.
As with other cancers, therapy may be prescribed that is intended to be curative removal or eradication of a cancer or palliative measures that are unable to cure a cancer but can reduce pain and suffering. More than one type of therapy may be prescribed. In such cases, the therapy that is added to enhance the effects of the primary therapy is referred to as adjuvant therapy.
An example of adjuvant therapy is chemotherapy or lung cancer signs and symptoms administered after surgical removal of a tumor in an attempt to kill any tumor cells that remain following surgery.