Once you have had tests that show you have lung cancer and whether it has spread, your doctor will tell you the stage of the cancer. This staging helps the doctor decide on the best treatment for you.
The expected outcome of your disease is called the prognosis, but it is only a prediction and some people do not find it helpful or even prefer not to know.
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Staging lung cancer
Working out how far the cancer has spread is called staging, and it helps your health care team recommend the best treatment for you.
The most common staging system for lung cancer is the TNM system. TNM stands for tumour-nodes-metastasis.
Each letter is assigned a number (and sometimes a or b) to show how advanced the cancer is. This information may be combined to give the lung cancer an overall stage of I, II, III or IV.
- Stages I and II generally include T1–2 N0–1 M0 tumours and are usually referred to as early lung cancer.
- Stage III covers any T N2–3 M0 tumours and is called locally advanced lung cancer.
- Stage IV refers to any T and N M1 tumours that are metastatic (advanced cancer) and have spread beyond the lung and regional lymph nodes.
The TNM system is complex, so if you have any questions please ask your doctor. Here is a brief explanation of the system:
‘T’ indicates the size of the tumour and the depth of any tumour invasion into the lung.
- T1a – tumour is less than 2 cmT (Tumour)
- T1b – tumour is between 2 cm and 3 cm
- T2a – tumour is between 3 cm and 5 cm
- T2b – tumour is between 5 cm and 7 cm
- T3 – tumour is more than 7 cm or has grown into the chest wall, mediastinal pleura, diaphragm or pericardium, or it has made the lung collapse
- T4 – tumour has grown into nearby structures, such as the mediastinum, heart, trachea, area where the main airway divides to go into each lung, oesophagus or the backbone, or two or more separate tumours are present in the same lobe of a lung
‘N’ shows if the tumour has spread to nearby lymph nodes, includes N0–3.
‘M’ shows if the tumour has spread to other parts of the body.
- M0 – cancer has not spread to distant parts of the body
- M1a – separate tumour in a contralateral lobe, tumour with pleural nodules or malignant pleural effusion
- M1b – cancer has spread to distant parts of the body, such as the liver or bones
Prognosis means the expected outcome of a disease.
You may wish to discuss your prognosis and treatment options with your doctor, but it is not possible for any doctor to predict the exact course of the disease. Instead, your doctor can give you an idea about the general prognosis for people with the same type and stage of cancer.
As in most types of cancer, the results of lung cancer treatment tend to be better when the cancer is found and treated early. See above for more information about staging lung cancer.
To work out your prognosis, your doctor will consider your test results; the type of lung cancer; the rate and extent of tumour growth; how well you respond to treatment; and other factors such as your age, fitness and overall health, and whether you’re currently a smoker.