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What is lung cancer?

Lung cancer begins when abnormal cells grow and multiply in an uncontrolled way in the lungs. Cancer that starts in the lungs is known as primary lung cancer. It can spread to the lymph nodes, brain, adrenal glands, liver and bones.

When cancer starts in another part of the body and spreads to the lungs, it is called secondary or metastatic cancer in the lung. This information is about primary lung cancer only.

What are the different types?

There are two main types of primary lung cancer. These are classified according to the type of cells affected.

  • non-small cell lung cancer (NSCLC) – NSCLC makes up about 85% of lung cancers. It may be classified as:
    • adenocarcinoma – begins in mucus producing cells; more often found in outer part of the lungs
    • squamous cell carcinoma – begins in thin, flat cells; most often found in larger airways
    • large cell undifferentiated carcinoma – the cancer cells are not clearly squamous or adenocarcinoma.
  • small cell lung cancer (SCLC) – SCLC makes up about 15% of lung cancers. It tends to start in the middle of the lungs and usually spreads more quickly than NSCLC.

Other types of cancer can also affect the lung area, but are not considered lung cancer. These include tumours that start in the space between the lungs (mediastinum) or in the chest wall.

Pleural mesothelioma is a cancer that affects the covering of the lung (the pleura). It is different from lung cancer and is usually caused by exposure to asbestos.

Download our booklet ‘Understanding Mesothelioma’

How common is lung cancer?

Each year, about 12,200 Australians are diagnosed with lung cancer. The average age at diagnosis is 72. It is the fifth most common cancer in Australia, accounting for 9% of all cancers diagnosed. More men than women develop lung cancer.

Featured resources

Lung Cancer - Your guide to best cancer care

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Understanding Lung Cancer

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This information is reviewed by

This information was last reviewed in October 2020 by the following expert content reviewers: A/Prof Nick Pavlakis, President, Australasian Lung Cancer Trials Group, President, Clinical Oncology Society of Australia, and Senior Staff Specialist, Department of Medical Oncology, Royal North Shore Hospital, NSW; Dr Naveed Alam, Thoracic Surgeon, St Vincent’s Private Hospital Melbourne, VIC; Prof Kwun Fong, Thoracic and Sleep Physician and Director, UQ Thoracic Research Centre, The Prince Charles Hospital, and Professor of Medicine, The University of Queensland, QLD; Renae Grundy, Clinical Nurse Consultant – Lung, Royal Hobart Hospital, TAS; A/Prof Brian Le, Director, Palliative Care, Victorian Comprehensive Cancer Centre – Peter MacCallum Cancer Centre and The Royal Melbourne Hospital, and The University Of Melbourne, VIC; A/Prof Margot Lehman, Senior Radiation Oncologist and Director, Radiation Oncology, Princess Alexandra Hospital, QLD; Susana Lloyd, Consumer; Caitriona Nienaber, 13 11 20 Consultant, Cancer Council WA; Nicole Parkinson, Lung Cancer Support Nurse, Lung Foundation Australia.