Lung Cancer

Smoking is the most common cause of lung cancer, causing more than 85% of cases. Your risk of lung cancer from smoking is related to:

• how much you smoke
• how long you’ve been smoking
• when you started smoking
• the type of cigarettes you smoke

Other causes of lung cancer include:

• using tobacco - such as cigars, powdered (snuff) and chewing tobacco
• smoking cannabis - on its own or mixed with tobacco
• passive smoking
• exposure to certain chemicals - such as asbestos, arsenic and radioactive substances like radon gas
• previous lung disease

There are two main types of lung cancer: non-small-cell and small-cell lung cancer. These types of lung cancer are named after the cell the cancer starts in.

Non-small-cell lung cancer is the most common type, and makes up more than 80% of all lung cancer cases.

There are three types of non-small-cell lung cancer: squamous cell carcinoma, adenocarcinoma, or large cell carcinoma.

There are usually no signs or symptoms in the early stages of lung cancer. Symptoms tend to develop as the condition progresses, and can include:

• a persistent cough
• coughing up blood
• persistent breathlessness
• unexplained tiredness and weight loss
• persistent chest or shoulder pain
• loss of appetite
• repeated chest infections

Lung cancer survival rates can vary from person to person and depend on several factors. These include:

• the type of cancer
• how far the cancer has spread at the time of diagnosis
• your level of fitness
• if you have had previous treatment for the cancer

In general, around one in three people with lung cancer live for at least a year after diagnosis. Around one in 20 people live at least 10 years.

Lung cancer survival rates are best when the cancer is diagnosed and treated at an early stage, when it is still small and has not spread.

There are four stages of lung cancer. Each stage represents how big the cancer is and how far it has spread through the body.

Stage 4 is the most advanced stage of lung cancer. It means that any of the following has happened:

• the cancer is found in both lungs
• the cancer has spread to another part of the body (such as the bones, liver or brain)
• cancer cells are found in the fluid surrounding your heart or lungs

There are two main types of lung cancer: non-small-cell and small-cell lung cancer. These are named after the type of cell the cancer started in.

Non-small-cell lung cancer is the most common type and it makes up more than 80% of all lung cancer cases.

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

• squamous cell carcinoma - develops in the flat cells that cover the surface of your airways and grows near the centre of the lungs
• adenocarcinoma - develops in the mucus-making gland cells that line the airways
• large cell carcinoma - the cancer cells look large and round under the microscope

Small-cell lung cancer is less common, making up between 10% and 20% of all lung cancer cases. This type of lung cancer tends to spread early on and is usually caused by smoking.

Most people with lung cancer do not experience any signs or symptoms in the early stages. However, as the condition progresses, symptoms may develop. These symptoms can include:

• a persistent cough
• coughing up blood
• persistent breathlessness
• unexplained tiredness and weight loss
• persistent chest or shoulder pain
• loss of appetite
• repeated chest infections

If the cancer has not spread, having surgery to remove the tumour may help. Radiotherapy can be used to treat certain types of lung cancer.

When the cancer has already spread, treatment such as chemotherapy can help to improve your symptoms and slow down the progression of lung cancer.

Your risk of lung cancer may be higher if you have a parent or sibling who has had lung cancer. However, the exact role your genes play in your risk of lung cancer is currently unclear.