Limited and extensive stage (small cell lung cancer)

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.

To help your doctor decide on the best treatment for you, they might use a simpler and older system to stage small cell lung cancer. This describes your cancer as limited disease or extensive disease.

The American Joint Committee on Cancer (AJCC) now recommends using the TNM system to stage small cell lung cancer. Your doctor can tell you more about which system they use.

Limited disease

Doctors describe small cell lung cancer as limited if the cancer is contained in a single area on one side of the chest. And the cancer can be treated with radiotherapy to just one area.

This generally means your cancer:

• is only in one lung
• may be in nearby lymph nodes – for example, in the centre of the chest or above the collar bone

If you have limited disease you are likely to have chemotherapy as well as radiotherapy treatment. This is usually given as radiotherapy at the same time as the first two cycles of chemotherapy (chemoradiotherapy).

If your cancer is at a very early stage, you might be able to have surgery to remove the part of the lung containing the cancer. This is called a lobectomy. But surgery isn’t used very often for small cell lung cancer. If you do have surgery, you usually have chemotherapy afterwards and might also have radiotherapy.

Your doctor might also suggest that you have radiotherapy to the brain to reduce the risk of cancer spreading there. This is called prophylactic cranial irradiation.

Extensive disease

Extensive disease means that the cancer has spread beyond a single area that can be treated with radiotherapy.

It might have spread:

• within the chest (either to the other lung or to lymph nodes further away from the cancer)
• to other parts of your body
• into the space between the layers of tissue that surrounds the lungs (pleural space), causing a build up of fluid (malignant pleural effusion)
• in between the heart and the sack (pericardium) that surrounds the heart, causing a build up of fluid (malignant pericardial effusion)

The main treatment for extensive stage disease is chemotherapy with or without immunotherapy. Your doctor might also suggest radiotherapy to the brain to reduce the risk of cancer spreading there. Instead of radiotherapy to the brain, they might suggest observation through routine MRI scans.

TNM and number staging systems

Staging using limited and extensive disease is becoming less common. Doctors are using the TNM and number staging systems more regularly. This is because we are learning more about SCLC and how best to treat the different stages.

TNM and number stages for limited and extensive stage SCLC

The TNM staging system stands for Tumour, Node, Metastasis.

• T describes the size of the tumour (cancer)
• 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

Limited disease

In the TNM staging system limited disease is the same as any T, any N, M0.

This generally means stage 1, 2 and 3 SCLC.

Extensive disease

Extensive disease is the same as:

• any T, any N, M1a
• any T, any N, M1b
• any T any N, M1c

Some people might have T3 or T4 tumours that are too big to be treated with radiotherapy to just one area.

Generally, extensive disease means a stage 4 small cell lung cancer.

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