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.

Expert review and references

  • Cancer Care Ontario. Small Cell Lung Cancer Treatment Pathway Map. 2019: Version 2019.05.
  • American Cancer Society. Treating Small Cell Lung Cancer. 2019 : https://www.cancer.org/cancer/lung-cancer/treating-small-cell.html.
  • National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Small Cell Lung Cancer (Version 1.2021). 2020.