INTRODUCTION: Lung cancer is a disease of uncontrolled cellular growth in tissues of the lungs. It is one of the most commonly occuring cancers in the United States, accounting for approximately 15 percent of all cases, or 170,000 new cases every year. It is also the leading cancer killer in America, taking more lives each year than breast, prostate and colorectal cancers combined, according to the American Cancer Society. In the US it is the leading cause of cancer deaths in women and is responsible for as many deaths as breast and all gynecological cancers combined.

SMOKING: Smoking, radon, and second hand smoke are the leading causes. Smoking causes an estimated 160,000* deaths in the US. Smoking leads to 85 percent to 90 percent of all lung cancers.

Smoking affects those who do not smoke by exposing them to second hand smoke. If a person ceases smoking, the chance of developing lung cancer steadily decreases as damage to the lungs is repaired and contaminant particles are gradually removed.

RADON GAS: A colorless and odorless gas produced by the breakdown of radioactive radium, which is the decomposition product of uranium, found in the earth's crust.

Radon leads the way as the number one cause of lung cancer among non-smokers, according to EPA estimates. It causes between 15,000 and 22,000 deaths each year in the United States -- 12 % of all lung cancer deaths are linked to radon.

RISK FACTORS: Include smoking cigarettes or cigars, now or in the past. Not all cases are due to smoking, but the role of passive smoking is increasingly being recognized as a risk factor, leading to policy interventions to decrease undesired exposure of non-smokers to others' tobacco smoke.

A smoker who is also exposed to radon has a much higher risk of lung cancer. The more cigarettes you smoke a day and the earlier you started, the greater your risk of developing lung cancer. High levels of pollution, radiation and asbestos exposure may also increase your risk.

SYMPTOMS: Include Chronic cough, Hoarseness, Coughing up blood, Weight loss & loss of appetite, Shortness of breath, Fever without a known reason, Wheezing, Repeated bouts of bronchitis or pneumonia and Chest pain.

About 10% of people do not have symptoms at diagnosis; these cancers are incidentally found on routine chest x-rays. In fact, lung cancer can spread outside the lungs without causing any symptoms.

TREATMENT: Treatment depends on the cancer's specific cell type, how far it has spread, and the patient's performance status. It also depends on the stage, or how advanced it is.

Treatment choices should be discussed with Your Physician. It can include drugs, radiation and surgery. In the last few years, different molecular targeted therapies have been developed as treatments.

CONCLUSION: Lung cancer is the second most common form of cancer in most western countries, and it leads the way in cancer-related cause of death. It is the most common cause of cancer deaths in both men and women, accounting for nearly a third of cancer deaths yearly in the US.

It has become the subject of an enormous amount of research. Although the number of men dying from it is declining in western countries, it is actually increasing for women due to the increasing habit of smoking by this group. We already know that the best way to prevent lung cancer is to quit (or never start) the habit. Three to five years after quitting, the risk of getting the disease is cut in half.