Lung cancer

Lung cancer is one of the most common and serious types of cancer. Symptoms of lung cancer include:

• coughing,
• unexplained weight loss,
• shortness of breath, and
• chest pain.

The lungs

The lungs are a pair of sponge-shaped organs that are located in the centre of the chest. They have two main purposes:

• to transfer oxygen into the blood when you breathe in, and
• to expel carbon dioxide out of the blood when you breathe out.

The lungs are made up of a series of sections called lobes. The left lung consists of two lobes, and the right lung is larger and consists of three lobes.

Types of lung cancer

Cancer that begins in the lungs is known as primary lung cancer. Cancer that begins in another part of the body before spreading to the lungs is known as secondary lung cancer. This article focuses on primary lung cancer.

There are two main types of primary lung cancer which are classified by the type of cells that the cancer starts in. These are:

• non-small cell lung cancer, and
• small cell lung cancer.

Non-small cell lung cancer

Non-small cell lung cancer is the most common type of lung cancer, accounting for around 80% of all cases.

Small cell lung cancer

Small cell lung cancer is less common and accounts for around 20% of all cases. Small cell lung cancer is more aggressive than non-small cell lung cancer, and it usually spreads faster.

How common is lung cancer?

Lung cancer is the second most common cancer (after skin cancer) in England and Wales, with an estimated 31,000 new cases being diagnosed every year.

Lung cancer is the most common cause of cancer-related death in both men and women. During 2007, there were 29,660 deaths in England and Wales as a result of lung cancer.

Lung cancer is primarily a disease that affects older people. Cases are rare in people who are under 40 years of age, but the rates of lung cancer rise sharply with age. The most common age range that lung cancer is diagnosed is between 70-74 years of age.

Smoking is the single biggest risk factor for lung cancer, accounting for an estimated 85-90% of cases. People who smoke more than 20 cigarettes a day are 20 times more likely to develop lung cancer than non-smokers.

Outlook

Lung cancer does not usually cause any noticeable symptoms until it has spread through much of the lungs and/or into other parts of the body. This is known as advanced, or metastatic, lung cancer. Therefore, the outlook for lung cancer is poor in comparison to other types of cancer.

Statistics show that only 25% of people with lung cancer will survive for at least a year after receiving a diagnosis, and just 7% will survive for at least five years.

However, survival rates can vary widely depending on how far the cancer has spread (the stage of the cancer) at the time of the diagnosis. See the ‘diagnosis' section for more information about staging and survival rates.

Lung cancer is usually treated using a combination of chemotherapy, radiotherapy, and surgery.