About Lung Cancer

In this section you can find out more about:

This will help to give you a better understanding of the disease. Remember, if you want to know more or you have further questions, note them down and speak to your medical professional.

What is Lung Cancer?

Lung cancer occurs when the cells in the lung start to grow in an out-of-control fashion and form a tumour.


Lung cancer usually starts in the lining of the main air tubes, called the bronchi and bronchioles, but it can also spread to the lymph nodes and the chest wall.

There are three main types of lung cancer. They are classified according to the type of cells present in the tumour. These are:

  • Non-small cell lung cancer (NSCLC): This the most common kind of lung cancer making up about 85% of all lung cancer cases. Non-small cell lung cancer can be divided into three main types. These are:
  • Squamous cell carcinoma: This develops in the cells that line the airways. It is often caused by smoking and makes up about 25–35% of lung cancers.
  • Adenocarcinoma: This originates in the cells that produce mucous in the lining of the airways. It makes up about 40% of lung cancers.
  • Large cell carcinoma: This cancer is known for the large, rounded cells seen when they are examined under a microscope. It makes up about 10–15% of all lung cancer cases.

Other, much less common, forms of non-small cell lung cancer are adenosquamous carcinoma and sarcomatoid carcinoma.

  • Small cell lung cancer (SCLC): This is a less common form of lung cancer and is so-called because the cells of the tumour are small. About 10% of lung cancers will be small cell.

  • Lung carcinoid tumour: This is also known as lung neuroendocrine tumour because it is actually a cancer of the neuroendocrine system. It makes up about 5% of lung cancers.

A further type of cancer that occurs in the lungs is mesothelioma, which is usually caused by exposure to asbestos.

Who gets Lung Cancer?

Lung cancer is common and each year around 2,000 New Zealanders will be diagnosed with the disease.1 Lung cancer affects both men and women.

Lung cancer is strongly associated with smoking. However, just because you’ve never smoked doesn’t mean you can’t get lung cancer. “Passive” smoking or being around people who smoke regularly can also increase your risk.

Smoking is only one risk factor and while smoking increases your risk, it does not mean that you will get lung cancer. Check with your doctor if you have any concerns.