What are the stages of lung cancer?

The stage of a cancer describes its size and position, and if it has spread from where it started. Knowing the stage helps your doctors advise you on the best treatment for you.

Doctors use the same staging system for non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Your doctor may tell you the stage of the lung cancer using a number staging system, from 1 to 4.

The lung cancer stages are based on:

  • the size of the tumour
  • whether it has spread into nearby parts of the lung, or outside the lung
  • whether it is in lymph nodes nearby, in the chest, or further away
  • whether it has spread further outside the lung or to other parts of the body.

The staging for lung cancer also looks at other things, such as whether the lung has partly or fully collapsed.

Most of the number stages are also sub-divided. We have not included these here, to try to keep it simple. Your doctor or nurse can explain more about your stage of lung cancer.

Stage 1

This is when the cancer is no bigger than 4cm. It has not spread outside the lung or to any lymph nodes.

This is called early or localised lung cancer.

Stage 2

The cancer can be different sizes. It may have spread to:

  • nearby lymph nodes
  • other parts of the lung
  • areas just outside the lung.

Stage 2 lung cancer is usually called locally advanced lung cancer.

Stage 3

The cancer can be any size and has usually spread to lymph nodes. It may also be growing into:

  • other parts of the lung
  • the airway
  • surrounding areas outside the lung.

It may also have spread to tissues and structures further from the lung. But it has not spread to other parts of the body.

Stage 3 lung cancer is usually called locally advanced lung cancer.

Stage 4

The cancer can be any size. It may have spread to lymph nodes and one of the following:

  • The cancer has spread to the lung on the other side.
  • There are cancer cells in fluid in the pleura or around the heart.
  • The cancer has spread to another part of the body, such as the liver, bones or brain.

Stage 4 lung cancer is called metastatic or secondary lung cancer.

Staging of small cell lung cancer (SCLC)

Doctors may divide small cell lung cancers (SCLC) into two stages:

Limited stage

The cancer cells can be seen in one lung and in nearby lymph nodes.

Extensive stage

The cancer has spread outside the lung, to the chest area or to other parts of the body.

SCLC can spread outside the lung quite early on. Because of this, doctors usually treat SCLC as if it has spread, even if scans do not show this. Some cancer cells are likely to have spread through the blood or lymphatic system. But this can be too small to show up on scans.