This is when abnormal "malignant" cells divide and grow in an uncontrolled fashion in the lung tissue. The effect of this is to destroy normal lung tissue and block off the breathing tubes. There are several types of lung cancer.  The most common cause is cigarette smoke; however exposure to asbestos, marijuana smoke and a number of other chemicals can also increase your risk of developing cancer.

Common signs and symptoms:

• Persistent cough or cough that worsens with time
• coughing up blood
• chest pain
• loss of appetite and weight
• tiredness
• repeated bronchitis or pneumonia or chest infections not improving with antibiotic therapy.

Diagnosis

To diagnose lung cancer we will need to take a history, examine you and undertake tests.  The aim of the tests is to confirm the diagnosis and find out what type of cancer it is which usually involves obtaining some tissue or fluid for examination. It is important to realise that a chest X-ray is often a reasonable screening test but not so reliable at offering a conclusive diagnosis. As such the tests may actually exclude a diagnosis of cancer.

Tests you are likely to have include:

• chest X-ray. Usually already completed by your GP and often the first test that raises the question of lung cancer
• CT scans with or without fine needle aspirate (see below)
• bronchoscopy  (see below)
• lung function tests (see below).

Treatment

If lung cancer is diagnosed, a process known as staging determines the extent of the disease. Knowing the type and stage of cancer means the doctor can plan your treatment.

Different treatment options include:

• surgery.  The type of surgery depends on the size and type of cancer and depending on the extent of cancer cure rates of between 20 and 90% are obtained.
• radiotherapy is a form of high energy radiation (X-ray) that kills cancer cells. If the cancer is small then cure rates of up to 35% have been obtained.
• chemotherapy is the use of drugs aimed at killing cancer cells.

The aim of treatment is to keep the person as well as possible and to prolong life, though cures are very rare.

If you have a lung cancer there will be ongoing follow-up with a number of specialists and nurses throughout your treatment and afterwards.

For more information about lung cancer see www.cancernz.org.nz; Australian Lung Foundation.