TNM staging for lung cancer

Staging systems

The TNM system is the most common way to stage lung cancer. Doctors may also use the number system.

Find out about the number staging system

A simpler and older staging system is sometimes used for staging small cell lung cancer. It describes the cancer as limited disease or extensive disease. The American Joint Committee on Cancer (AJCC) now recommends using the TNM system to stage both small and non small cell lung cancer.

Read more about limited and extensive stage small cell lung cancer

There are 4 categories – T1 to T4.

TX means the main cancer (primary) can’t be assessed. It doesn't show on scans but there might be cancer cells present in spit or in fluid taken from the lung.

T0 means there is no sign of cancer.

Tis means an area of cancer cells contained within the top layers of the inner lining of the lungs. This is also called carcinoma in situ.

T1

T1 means the cancer is contained within the lung.

T1mi is a staging description for a type of non small cell lung cancer called adenocarcinoma. It means minimally invasive adenocarcinoma. The cancer is no more than 3cm at its widest part. It’s grown no further than 0.5cm into deeper lung tissue.

It is divided into T1a, T1b, and T1c according to the diameter of the cancer.

T1a means the cancer is 1cm or less at its widest part.

T1b means the cancer is between 1cm and 2cm across.

T1c means the cancer is between 2 and 3 cm across.

T2

T2 can mean different things.

The cancer is between 3cm and 5cm across.

Or the cancer is 4cm or less and has one or more of the following features:

• it involves the inner lining of the chest cavity (the visceral pleura)

• it has grown into the nearby lobe

• it involves the main airway (the main bronchus) but is not close to the area where the bronchus divides to go into each lung (carina), or part or all of the lung has collapsed or is blocked due to inflammation

T2 is divided into T2a and T2b.

T2a means the cancer is between 3cm and 4cm, or 4cm or less with one or more of the features listed above.

T2b means the cancer is between 4cm and 5cm with or without the features listed above.

T3

T3 can mean different things.

The cancer is between 5cm to 7cm.

Or the cancer is 7cm or less and has one or more of the following features:

• it has grown into the outer lining of the chest cavity (the parietal pleura) or the chest wall (the protective structure around the lungs and other organs in the chest)

• it has grown into the outer covering of the heart (the pericardium) or the nerve close to the lung (phrenic nerve)

• there is more than one tumour in the same lobe of the lung

T4

T4 can mean different things.

The cancer is bigger than 7cm.

Or it is any size and has one or more of the following features:

• it has grown into the area between the lungs in the middle of the chest (the mediastinum), the thymus gland, the windpipe (trachea), the area where the main airway divides to go to each lung (carina), the nerve that controls the voice box, a big nerve that runs between the brain, heart and digestive system (vagus nerve), the food pipe (oesophagus), or muscle below the lungs (the diaphragm)

• it has grown into the heart or major blood vessels nearby

• it has grown into blood vessels under the collar bone, the spine or a spinal bone, or nerves in the neck or shoulder

• there is more than one tumour in different lobes of the same side of the lung

NX means that the lymph nodes can’t be assessed.

N0 means that the lymph nodes don’t contain cancer cells.

N1

N1 means the cancer has grown into lymph nodes within the lung or in lymph nodes in the area where the lungs join the airway (the hilum) or into both areas. These lymph nodes are on the same side as the cancer.

N2

N2 is divided into N2a and N2b.

N2a means there is cancer in a single area of lymph nodes just under where the windpipe branches off to each lung (subcarinal) or in the centre of the chest (mediastinum). These lymph nodes are on the same side as the cancer.

N2b means there is cancer in several areas of lymph nodes in the centre of the chest (mediastinum). The cancer may or may not have grown into lymph nodes just under where the windpipe branches off to each lung (subcarinal). These lymph nodes are on the same side as the cancer.

N3

N3 means there is cancer in lymph nodes:

• in the centre of the chest on the opposite side of the affected lung

• just under where the windpipe branches off to each lung (subcarinal) on the opposite side of the affected lung

• near muscles in the neck on one or both sides

• above the collar bone on one or both sides

M0

M0 means the cancer hasn’t spread to any other part of the body.

M1

M1 is divided into M1a, M1b and M1c

M1a means one or more of the following:

• the cancer has spread to the two layers that cover the lung (pleura) or the layer around the heart (pericardium)

• there is fluid around the lung or heart that contains cancer cells – this is called a malignant pleural effusion or a malignant pericardial effusion

• the cancer has spread into the opposite lung

M1b means that there is a single area of cancer outside the chest (for example one area in the liver or brain) or as a single distant (non-regional) lymph node.

M1c is divided into M1c1 and M1c2.

M1c1 means the cancer has spread outside the chest to more than one area in one organ, such as to several areas in a single bone or several areas in several bones.

M1c2 means the cancer has spread outside the chest to several organs.

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)

• any gene mutations your lung cancer cells might have

• where the cancer is 

• how well you are (your ​performance status)

• other health conditions that you have

The stage of the cancer and these other factors can also give an idea of your outlook (prognosis).

Treatment might include one or more of the following:

• chemotherapy

• radiotherapy

• chemoradiation – chemotherapy with radiotherapy

• surgery – to remove part or all of your lung

• chemotherapy combined with immunotherapy

• targeted cancer drugs

• immunotherapy

• radiofrequency ablation

• photodynamic therapy

• symptom control treatment (supportive or palliative care)

Find out about treatment for lung cancer

Research and clinical trials

Doctors are always trying to improve the results of treatment and reduce side effects. They might offer you treatment as part of a clinical trial.

Research and clinical trials for lung cancer treatment