Lung cancer

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Staging small cell lung cancer

Staging is a way to describe or classify a cancer based on the extent of cancer in the body. Extent includes the size of the tumour and where the cancer is in the body. Your healthcare team uses the stage to plan treatment and estimate the outcome (your prognosis).

Small cell lung cancer is divided into 2 stages – limited and extensive.

Limited stage small cell lung cancer is found only on one side of the chest. This could include cancer that is found in part of one lung and may have spread to the lymph nodes on the same side as the tumour. It may also include the lymph nodes in the centre of the chest (mediastinum). Limited stage small cell lung cancer can be treated with radiation to a single area of the body.


Extensive stage small cell lung cancer has spread widely in the lung with the tumour, to the other lung, to the lymph nodes on the other side of the chest from the tumour, or to other parts of the body. It may also include cancer that has spread to the fluid around the lung. Most people with small cell lung cancer are diagnosed with extensive stage cancer because the cancer spreads early and quickly, before it causes symptoms.

Small cell lung cancer can also be staged using the TNM system. Each stage is given a number from 1 to 4. Stages 1 to 4 are usually given as the Roman numerals I, II, III and IV. Generally, the higher the number, the more the cancer has spread. However, the TNM system is not used as often as the limited or extensive staging.

TNM staging system

A system used to describe the extent of cancer in the body (the stage) for most types of cancer.

T describes the size and extent of the tumour. N describes the extent of spread to regional lymph nodes. M describes the extent to which the cancer has spread (metastasized) to distant sites in the body.


Dr Roger Zemp Improving cancer detection with ultrasound and tiny droplets

Taking action against all cancers

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The latest Canadian Cancer Statistics report found that of all newly diagnosed cancers in 2017, half are expected to be lung, colorectal, breast and prostate cancers. Learn what you can do to reduce the burden of cancer.

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