Stage 4 lung cancer
What does the stage of a cancer mean?
The stage of a cancer tells you how big it is and whether it has spread.
Why do you need to know the stage of a cancer?
It helps your doctor decide which treatment you need.
What is stage 4 lung cancer?
Stage 4 lung cancer means the cancer has spread. This is also called advanced lung cancer.
What is the aim of treatment?
The aim of treatment is to control the cancer and help to reduce the symptoms. Treatment depends on what type of lung cancer you have, where it has spread and your health.
The stage of a cancer tells you how big it is and whether it has spread. Knowing the stage helps your doctor decide which treatment you need.
Stage 4 is part of the number staging system. It means that the cancer has spread. It is divided into stage 4A and 4B. It is also called advanced lung cancer.
Stage 4A can mean any of the following:
- there is cancer in both lungs
- the cancer is in the covering of the lung (the pleura) or the covering of the heart (pericardium)
- or there is fluid around the lungs or the heart that contains cancer cells

Or it can mean that there is a single area of cancer that has spread outside the chest to a lymph node or to an organ such as the liver or bone.

Stage 4B means that the cancer has spread to several areas in one or more organs.

TNM stages
The TNM staging system stands for Tumour, Node, Metastasis.
- T describes the size of the tumour
- N describes whether there are any cancer cells in the lymph nodes
- M describes whether the cancer has spread to a different part of the body
In the TNM staging system, stage 4 is the same as one of the following:
- Any T, Any N, M1a
- Any T, Any N, M1b
- Any T, Any N, M1c
Treatment
The stage of your cancer helps your doctor to decide which treatment you need. Treatment also depends on:
- your type of cancer (the type of cells the cancer started in)
- where the cancer is
- other health conditions that you have
The treatment for small cell lung cancer is different to the treatment for non small cell lung cancer.
Non small cell lung cancer
Treatment aims to control the cancer for as long as possible and help to reduce symptoms.
If you are well enough you might have:
- chemotherapy
- targeted cancer drugs
- immunotherapy
To control symptoms you might also have one or more of these treatments:
- external radiotherapy
- internal radiotherapy (brachytherapy)
- laser treatment
- freezing the tumour (cryotherapy)
- a rigid tube (called a stent) to keep the airway open
- light therapy (photodynamic therapy – PDT)
Small cell lung cancer
Treatment aims to control the cancer for as long as possible and help to reduce symptoms.
If you are well enough you usually have chemotherapy.
If the chemotherapy works well, you might have radiotherapy to your chest after chemotherapy.
After you finish treatment, you might have radiotherapy to your head. This treatment is called (PCR). You have this because it is quite common for small cell lung cancer to spread to the brain. The radiotherapy aims to kill any cancer cells that may have already spread to the brain but are still too small to see on scans.
You might have prophylactic cranial radiotherapy if:
- your chemotherapy or radiotherapy treatment has stopped your cancer growing
- you are well enough
To control symptoms you might also have one or more of these treatments:
- radiotherapy
- internal radiotherapy (brachytherapy)
- laser treatment
- freezing the tumour (cryotherapy)
- a rigid tube (called a stent) to keep the airway open
- light therapy (photodynamic therapy – PDT)