Lung cancer is a disease of uncontrolled cell growth in tissues of the lung. This growth may lead to metastasis, invasion of adjacent tissue and infiltration beyond the lungs. The vast majority of primary lung cancers are carcinomas of the lung, derived from epithelial cells. Lung cancer, the most common cause of cancer-related death in men and the second most common in women,[1][2] is responsible for 1.3 million deaths worldwide annually.

What causes lung cancer?

Smoking

The incidence of lung cancer is strongly correlated with cigarette smoking, with about 90% of lung cancers arising as a result of tobacco use. The risk of lung cancer increases with the number of cigarettes smoked over time; 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).

Lung cancer most commonly starts in the cells that line your lungs. Smoking causes the majority of lung cancers — both in smokers and in people exposed to secondhand smoke. But lung cancer also occurs in people who never smoked. In these cases, there may be no clear cause of lung cancer. Doctors have identified factors that may increase the risk.

Cancer that originates from lung cells is called a primary lung cancer. Primary lung cancer can start in the airways that branch off the trachea to supply the lungs (the bronchi) or in the small air sacs of the lung (the alveoli). Cancer may also spread (metastasize) to the lung from other parts of the body (most commonly from the breasts, colon, prostate, kidneys, thyroid gland, stomach, cervix, rectum, testes, bone, or skin).

Lung Cancer Symptoms

Lung cancer symptoms are commonly not experienced until the disease had advanced, sometimes delaying diagnosis. The symptoms of lung cancer also mimic the symptoms of other benign illnesses.

The most common lung cancer symptoms experienced are :

Onset of wheezing

Recurrent pneumonia or bronchitis

A persistent cough that does not go away

A sign is also an indication that something is not right in the body. But signs are defined as things that can be seen by a doctor, nurse, or other health care professional. Fever, rapid breathing rate, and abnormal breathing sounds heard through a stethoscope may be signs of pneumonia.

Lung Cancer Diagnosis

To help find the cause of symptoms, your doctor will evaluate your medical history, smoking history, exposure to environmental and occupational substances, and family history of cancer. Your doctor also will perform a physical exam and may recommend 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, your doctor must examine tissue.

How can I prevent lung cancer?

The best way to prevent lung cancer is to quit smoking, or to never start in the first place. You should try and avoid being around people who are smoking; and also avoid pipes, cigars, and marijuana. If you live in an area with radon, you should make sure there is adequate ventilation in your basement to get rid of it. Use a detector to make sure the radon levels are low.

Treatment Of Lung Cancer

Many factors must be taken into account to determine the best treatment for an individual diagnosed with lung cancer. The specific type of cell, the location of the lung tumor, the stage of the disease with possible metastasis (spread to other parts of the body), and the general health of the individual must be considered. Various treatment plans may include radiation therapy, chemotherapy, and/or surgery.