Lung Ca Biography
(Source google.com)
Lung cancer (also known as
carcinoma of the lung) is a disease characterized by uncontrolled cell growth
in tissues of the lung. If left untreated, this growth can spread beyond the
lung by process of metastasis into nearby tissue or other parts of the body.
Most cancers that start in the lung, known as primary lung cancers, are
carcinomas that derive from epithelial cells. The main types of lung cancer are
small-cell lung carcinoma (SCLC), also called oat cell cancer, and
non-small-cell lung carcinoma (NSCLC). The most common symptoms are coughing
(including coughing up blood), weight loss, shortness of breath, and chest
pains. The most common cause of lung
cancer is long-term exposure to tobacco smoke, which causes 80–90% of lung
cancers. Nonsmokers account for 10–15% of lung cancer cases, and these cases
are often attributed to a combination of genetic factors, and exposure to;
radon gas, asbestos, and air pollution
including second-hand smoke. Lung cancer may be seen on chest radiographs and
computed tomography(CT) scans. The diagnosis is confirmed by biopsy which is
usually performed bybronchoscopy or CT-guidance. Treatment and long-term
outcomes depend on the type of cancer, the stage (degree of spread), and the
person's overall health, measured byperformance status.
Common treatments include
surgery, chemotherapy, and radiotherapy. NSCLC is sometimes treated with
surgery, whereas SCLC usually responds better to chemotherapy and radiotherapy.
Overall, 15% of people in the United
States diagnosed with lung cancersurvive
five years after the diagnosis. Outcomes are worse in the developing world.
Worldwide, lung cancer is the most common cause of cancer-related death in men
and women, and is responsible for 1.38 million deaths annually, as of 2008. If
the cancer grows in the airways, it may obstruct airflow, causing breathing
difficulties. The obstruction can lead to accumulation of secretions behind the
blockage, and predispose to pneumonia. Depending on the type of tumor,
so-called paraneoplastic phenomena may initially attract attention to the
disease. In lung cancer, these phenomena may include Lambert–Eaton myasthenic
syndrome (muscle weakness due to autoantibodies), hypercalcemia, orsyndrome of
inappropriate antidiuretic hormone (SIADH). Tumors in the top of the lung,
known as Pancoast tumors, may invade the local part of the sympathetic nervous
system, leading to Horner's syndrome (dropping of the eyelid and a small pupil
on that side), as well as damage to the brachial plexus. Many of the symptoms of lung
cancer (poor appetite, weight loss, fever, fatigue) are not specific. In many
people, the cancer has already spread beyond the original site by the time they
have symptoms and seek medical attention. Common sites of spread include the
brain, bone, adrenal glands, opposite lung, liver, pericardium, and kidneys.
About 10% of people with lung cancer do not have symptoms at diagnosis; these
cancers are incidentally found on routine chest radiography. Cancer develops
following genetic damage to DNA and epigenetic changes. These changes affect
the normal functions of the cell, including cell proliferation, programmed cell
death (apoptosis) and DNA repair. As more damage accumulates, the risk of
cancer increases. particularly of cigarettes, is
by far the main contributor to lung cancer. Cigarette smoke contains over 60
known carcinogens, including radioisotopes from the radon decay sequence,
nitrosamine, and benzopyrene. Additionally, nicotine appears to depress the
immune response to cancerous growths in exposed tissue. Across the developed
world, 90% of lung cancer deaths in men during the year 2000 were attributed to
smoking (70% for women). Smoking accounts for 80–90% of lung cancer cases. Passive smoking—the inhalation of
smoke from another's smoking—is a cause of lung cancer in nonsmokers. A passive
smoker can be classified as someone living or working with a smoker. Studies
from the US , Europe, the UK , and Australia have consistently shown a
significantly increased risk among those exposed to passive smoke. Those who
live with someone who smokes have a 20–30% increase in risk while those who
work in an environment with second hand smoke have a 16–19% increase in risk.
Investigations of sidestream smoke suggest it is more dangerous than direct
smoke. Passive smoking causes about 3,400 deaths from lung cancer each year in
the USA .
Radon is a colorless and odorless
gas generated by the breakdown of radioactive radium, which in turn is the
decay product of uranium, found in the Earth's crust. The radiation decay
products ionize genetic material, causing mutations that sometimes turn
cancerous. Radon is the second-most common cause of lung cancer in the USA , after
smoking. The risk increases 8–16% for every 100 Bq/m³ increase in the radon
concentration. Radon gas levels vary by locality and the composition of the
underlying soil and rocks. For example, in areas such as Cornwall
in the UK
(which has granite as substrata), radon gas is a major problem, and buildings
have to be force-ventilated with fans to lower radon gas concentrations. The
United States Environmental Protection Agency (EPA) estimates one in 15 homes
in the US
has radon levels above the recommended guideline of 4 picocuries per liter .
Lung Ca Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
Lung Ca Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
Lung Ca Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
Lung Ca Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
Lung Ca Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
Lung Ca Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
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