Almost 90.5% of lung cancers are smoking-related. Quitting smoking significantly reduces the risk of lung cancer, although former smokers are still more likely to get lung cancer than people who never smoked.

Exposure to other carcinogens, such as asbestos and radon gas, also increases the risk, especially in combination with smoking.

What is lung cancer?

Lung cancer is the uncontrolled growth of abnormal cells in one or both of the lungs. While normal lung tissue cells reproduce and develop into healthy lung tissue, these abnormal cells reproduce rapidly and never grow into normal lung tissue.

Lumps of cancer cells (tumors) then form and disrupt the lung, making it difficult to function properly. Only 15% of lung cancer cases are found at the early stage, and survival rates decline dramatically after the cancer has spread to other organs.

Types of lung cancer

Cancers that begin in the lungs are divided into two major types: non-small cell and small cell. Both grow and spread in different ways and are treated differently. More common than small cell lung cancer, non-small cell lung cancer generally grows and spreads slowly.

There are three main types of non-small cell lung cancer:

• Squamous cell carcinoma (also called epidermoid carcinoma)
• Adenocarcinoma
• Large cell carcinoma

Sometimes called oat cell cancer, small cell lung cancer is less common and grows quickly. It also is more likely to spread to other organs in the body

Lung cancer symptoms

It can take years for any signs of lung cancer to appear, and when they do, they are often confused with less serious conditions. Obvious symptoms usually don't occur until the disease has reached an advanced stage.

Consult a doctor if you are experiencing any of the following symptoms:

• Persistent or intense smoker’s cough
• Any cough that persists for more than two weeks
• Chronic chest, shoulder, or back pain
• Change in color or volume of mucus or phlegm
• Blood in mucus or phlegm
• Loss of appetite
• Swelling in the neck and face
• Wheezing, hoarseness, or shortness of breath
• Recurrent bronchitis or pneumonia
• Difficulty breathing
• A harsh sound with each breath
• Headaches, bone pain, or aching joints
• Chronic fatigue
• Unexplained weight loss

See also:

• Prevalence and prevention
• Causes and risk factors
• Detection and diagnosis
• Treatment options
• Prognosis
• Support
• Phil beats lung cancer