Staging of lung cancer

Staging of Lung Cancer

The stage of a cancer tells the doctor how far a cancer has spread. It is important because treatment is often decided according to the stage of a cancer. All staging for cancer includes information on the size of the tumour, whether there is cancer in the lymph nodes and whether the cancer has spread anywhere else.

There are different staging systems for cancer. You are most likely to be told the number stage of your cancer. This is a system that groups lung cancers into one of 4 groups, stages 1 to 4, depending on how far the cancer has progressed. As this system has developed, it has become a little more complicated. Stages 1 to 3 are now divided into subgroups. There is information below about the number stages of non small cell lung cancer.

Staging for small cell lung cancer can be even simpler with only two stages - limited diseaes and extensive disease. There is more about these two stages of small cell lung cancer below.

Between themselves, doctors most often use the TNM staging system. This is quite detailed and can tell the doctor the size of the primary cancer, whether it has spread to lymph nodes and whether it has spread anywhere else in the body.
The stages of non-small cell cancer
Non-small cell cancer can be divided into four stages

Stage I

This means the cancer is localised. There is no cancer in any lymph nodes.

Stage 1 can be divided into 1A and 1B. Stage 1A means the tumour is small (3cm or less across). Stage 1B means the cancer is larger or that it is growing in the main airway of the lung (the main bronchus). Stage 1B includes cancers that have grown into the inner covering of the lung or caused a partial collapse of the affected lung.

Stage 2

Stage 2 is divided into stages 2A and 2B. Stage 2A means the cancer is small, but has spread to the lymph nodes closest to the affected lung.

Stage 2B can mean one of two things

The cancer in the lung is larger than 3cm across and there is cancer in the lymph nodes nearest the affected lung or

There is no cancer in the lymph nodes but the cancer has grown into the chest wall, the outer covering of the lung, the muscle at the bottom of the chest cavity (the diaphragm) or the outer covering of the heart.

Stage 3 is divided into stages 3A and 3B. 3A can mean one of two things. There is cancer in nodes further away from the affected lung, but still on the same side of the chest. Or there is cancer only in lymph nodes nearest to the affected lung but the cancer has also spread to either the chest wall or the covering of the lung (pleura) or the middle of the chest (mediastinum).

3B cancer means one of 4 things

There is cancer spread to nodes on the other side of the chest or to nodes above either collarbone

There is more than one tumour in the affected lobe of your lung

The tumour has grown into another major structure in your chest, which could be the heart, the windpipe, the gullet (oesophagus) or a main blood vessel

There is a fluid collection around your lung that contains cancer cells (a malignant pleural effusion)

Stage 4 means the cancer has spread to another lobe of the lung from where it started or to another part of your body, for example the liver or bones.

The scans and tests you have done should give your doctor some idea of the stage of your cancer. But it may not be possible to be completely sure until you have had an operation. In most cases however the tests described in Diagnosing Lung Cancer are enough for your doctor to tell the stage.

The stages of small cell lung cancer
The TNM staging of small cell lung cancer is the same as for non-small cell lung cancer. But in practice, small cell lung cancers are often divided into just two groups. This is because small cell lung cancer often spreads quite early on. Even if the doctor cannot see any spread on your scans, it is likely that some cancer cells will have broken away and travelled through the bloodstream or lymphatic system. To be safe, doctors often prefer to treat small cell lung cancers as if they have spread, whether they can see any secondary cancer or not.

The two stages of small cell lung cancers are

Limited disease means cancer that can only be seen in one lung, in nearby lymph nodes or in fluid around the lung (pleural effusion)

Extensive disease means cancer that has spread outside the lung to the chest or to other parts of the body

Surgery is not usually used to treat small cell cancer, except in very early cases. Your doctor will probably suggest chemotherapy with or without radiotherapy. The scans and tests you have done at first will be used later to see how well you are responding to treatment.

Pleural effusion

A pleural effusion is fluid between the membranes covering the outside of the lungs - the pleura. The fluid takes up space and makes it impossible for the lung to expand fully when you breathe. If there is a lot of fluid, it can make you very breathless.

The fluid has to be checked for cancer cells. If it does have cancer cells, it is called a malignant pleural effusion and will affect the stage of your cancer. Occasionally, someone with lung cancer has fluid around the lung but the fluid doesn't contain cancer cells. If there are no cancer cells, it doesn't count towards your lung cancer stage.

In small cell lung cancer, pleural effusion containing cancer cells, but with no other signs of cancer spread is often classified as limited disease. But not all doctors agree on this. Some think that a pleural effusion may be better grouped as extensive disease.

In non small cell lung cancer, pleural effusion containing cancer cells means your cancer is considered to be at least stage 3B.

Staging of Lung Cancer

Stage I

Stage 2

Pleural effusion

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