Diagnosis

What tests are done (and why) to diagnose lung cancer?

Imaging: X-rays and scans

For most people, the first test to look for lung cancer will be a chest X-ray. This may be followed by a Computed Tomography (CT) scan of the chest to give a more detailed picture. 

Further tests will be needed to find out: 

  •  If anything unusual on a scan is lung cancer tumour 
  • The type of lung cancer  

The results of these tests will help your healthcare team decide which treatments could be used. Most tests and biopsies conducted will be outpatient appointments and will not require an overnight stay. 

If it is possible to offer curative treatment for your lung cancer, you will usually have additional scans before you start treatment. These are to check that your cancer has not spread elsewhere in your body and can include: 

  • CT scan of the brain 
  • Positron Emission Tomography (PET) scan which can show tumour activity around the body. 

The Roy Castle Foundation have some additional resources on Lung Cancer diagnosis – here 

The team looking after you will consider the size of the tumour and where it has spread to.  Treatment options will then be offered for discussion based on your fitness and priorities. 
 
The stage of your cancer depends on whether it has spread beyond the original site of the tumour within the lung. If the lymph glands in the chest look big or light up on a PET scan, the cancer may have spread into these glands. That can be checked by taking a sample (biopsy) from the glands. Even if they do contain tumour it may still be possible to consider surgery or radiotherapy to cure the cancer. Your team will discuss what the options might be. 
 
If the cancer has spread to other areas in the body this is called ‘metastatic’ or stage 4 disease. For most people with metastatic disease surgery or high dose radiation will not cure the caner. However, it can be possible to control the cancer with drug therapy. 
 
For some tumour sites the TNM staging system is being revised. Ask your team which system is in use and what this means for the stage of disease. More details on TNM staging here from CRUK. 
 
More information on Staging can be accessed here 
If a scan shows a suspected tumour the usual next step will be to take a sample of it. The sample will be tested by a pathology laboratory to find the type of cancer. 
 
A bronchoscopy will be used for tumours in the middle of the chest. You will be given medicines to help relax, then a tube is inserted through your nose down into the airways in the middle of the chest. If the scans show the tumour may have spread into the lymph glands these may be sampled too. 
 
For tumours near the edges of the lung it may be easier to take a sample from outside the body using a needle guided to the area using a CT scan. 
 
The pathology laboratory will examine the sample and confirm whether this is cancer and what type. Here are some useful resources on types of lung cancer: 
 
Types of lung cancer | Cancer Research UK 
Lung cancer | Macmillan Cancer Support 
 
 
The cancer cells taken from the sample may be tested for changes in the genes (mutations) or proteins which could be targets for treatment. This is called ‘molecular’ testing and can take longer to complete. For more information on targeted therapy see these resources: 
Targeted therapies for lung cancer | Macmillan Cancer Support 
Targeted and immunotherapy treatment for lung cancer | Cancer Research UK 
 
Sometimes it is not appropriate to put a person through investigations and biopsies if the results are not going to be helpful in caring for them. For example, if a scan shows advanced cancer or if someone is too unwell to be able to cope with treatment.  
 
In this case then the best care is to focus on symptom control and to avoid unhelpful additional tests. If the lung cancer team caring for you feel that this is the situation, they will explain why. 
If you have been diagnosed with lung cancer and are being considered for surgery further tests may be done. These check your heart and lungs are working well so you can cope with the removal of some of your lung. These might be breathing tests or exercise tests. 
 
If you are offered drug treatment for your lung cancer, then some drugs may have side effects on your kidneys or your immune system. These will be checked before and during drug treatment to avoid complications. Cancer drugs can also interact with some medications that you are taking for other health conditions.  
 
Occasionally the first sign of lung cancer can be back pain and weakness in the legs. If the cancer has caused damage to the spine, then an MRI scan may be done to determine the site of the problem and to arrange urgent treatment for this.