Your doctors will perform a number of tests to make a diagnosis, and work out whether the cancer has spread beyond the lung. The test results will help them recommend a treatment plan for you.
To investigate abnormal symptoms, the first test is usually an x-ray, often followed by a CT scan. You may also have a test to check how your lungs are working and blood tests to check your overall health.
A chest x-ray is painless and can show tumours 1 cm wide or larger. Small tumours may not show up on an x-ray or may be hidden by other organs within the chest cavity. After a chest x-ray, you may need more detailed tests.
A CT (computerised tomography) scan uses x-ray beams to take many pictures of the inside of your body and then a computer compiles them into a cross-sectional picture. This method can detect smaller tumours than those found by chest x-rays, and provides detailed information about the tumour, the lymph nodes in the chest, and other organs.
"I think the doctors knew I had cancer based on the shadow on my CT scan. But they didn't tell me right away. I had to wait two weeks until I had a bronchoscopy and wash." - James
CT scans are usually done at a hospital or radiology clinic. You may be asked to fast (not eat or drink) for several hours before the scan to make the pictures clearer and easier to read. Before the scan, you will be given an injection of dye into a vein in your arm. This dye is known as the contrast and it makes the pictures clearer. The contrast may make you feel hot all over and leave a bitter taste in your mouth, and you may feel a sudden urge to pass urine, but these sensations won't last long.
The CT scanner is a large, doughnut-shaped machine. You will lie flat on a table that moves in and out of the scanner. The scan is painless and takes only 10–20 minutes, but you will also need to prepare for and wait for the scan.
Before having scans, tell the doctor if you have any allergies or have had a reaction to contrast during previous scans. You should also let them know if you are diabetic, have kidney disease or are pregnant.
Lung function test (spirometry)
This test checks how well the lungs are working. It measures how much air the lungs can hold and how quickly the lungs can be filled with air and then emptied. You will be asked to take a full breath in and blow out into a machine called a spirometer.
A sample of your blood will be tested to check the number of cells (full blood count) and to see how well your kidneys and liver are working.
Tests to confirm diagnosis
If a tumour is suspected after an x-ray or CT scan, you will need further tests to work out whether it is lung cancer.
A biopsy is the usual way to confirm a lung cancer diagnosis. A small sample of tissue is taken from the lung and/or nearby lymph nodes, then a specialist doctor called a pathologist examines the sample under a microscope. There are various ways to take a biopsy.
CT-guided lung biopsy
Using a CT scan for guidance, the doctor inserts a needle through the chest wall to remove a small piece of tumour from the outer part of the lungs. You will be observed for a few hours afterwards, as there is a small risk of damaging the lung.
This allows the doctor to look inside the large airways (bronchi) using a bronchoscope, a flexible tube with a light and camera. You will have sedation or a general anaesthetic, then the doctor will pass the bronchoscope into your nose or mouth, down the trachea (windpipe) and into the bronchi. If the tumour is near the bronchi, samples of cells can be collected with a washing or brushing technique. During "washing", fluid is injected into the lung and removed for examination. "Brushing" uses a brush-like instrument to remove some cells from the bronchi.
Endobronchial ultrasound (EBUS)
This is a bronchoscopy that allows the doctor to see cancers deeper in the lung. It can also take samples of cells from a tumour or a lymph node in the middle of your chest or next to the airways, or from the outer parts of the lung.
You will have sedation or a general anaesthetic, and the doctor will use a bronchoscope with a small ultrasound probe on the end. The ultrasound probe uses soundwaves to create pictures that show the size and position of the tumour and allow the doctor to measure it.
After an EBUS, you may have a sore throat or cough up a small amount of blood. These side effects usually pass quickly, but tell your medical team how you are feeling so they can monitor you.
This is not used as often as other biopsy methods, but is sometimes used if a sample is needed from the lymph nodes found between the lungs (mediastinum). You will have a general anaesthetic, then a small cut (incision) will be made in the front of your neck and a thin tube passed down the outside of the trachea. A mediastinoscopy is usually a day procedure, but you may need to stay overnight in hospital for observation.
If other tests are unable to provide a diagnosis, you may have a thoracoscopy. This uses a thoracoscope, a tube with a light and camera, to take a tissue sample from the lungs. It is usually done under general anaesthetic with a type of keyhole surgery called videoassisted thoracoscopic surgery ( VATS). After VATS, you will have a drain coming from your side and stay in hospital for a few days. Sometimes a simpler procedure called a medical thoracoscopy can be done as a day procedure under sedation.
Biopsy of neck lymph nodes
A sample of cells may be taken from the lymph nodes in the neck with a thin needle. This is done using ultrasound for guidance.
A new technique known as liquid biopsy involves taking a blood sample and examining it for signs of disease. At this stage, however, liquid biopsy is not a routine way to diagnose lung cancer.
In some circumstances, such as if you aren't well enough for a biopsy, mucus or fluid from your lungs may be checked for abnormal cells.
This test examines a sample of mucus (sputum) from your lungs. Sputum is different to saliva as it contains cells that line the airways. To collect a sample, you will be asked to cough deeply and forcefully into a container. This can be done in the morning at home. The sample can be refrigerated until you take it to your doctor, who will send it to a laboratory to check under a microscope.
Also known as pleurocentesis or thoracentesis, a pleural tap is a procedure to drain fluid from around the lungs. While it is often done to ease breathlessness, the fluid can be tested for cancer cells. It is mostly performed under local anaesthetic using ultrasound for guidance. As with all biopsies, the results need to be interpreted along with the results of physical examination, blood and breathing tests, and imaging tests such as x-ray and CT scan.
The biopsy sample may be tested for genetic changes or specific proteins in the cancer cells (biomarkers). The tests are known as molecular tests and help work out which drugs may be most effective in treating the cancer.
Genes are found in every cell of the body and are inherited from both parents. If something triggers the genes to change (mutate), cancer may start growing. A mutation that occurs after you are born is not the same thing as genes inherited from your parents. The most common genetic mutations seen in non-small cell lung cancer are changes in the EGFR (epidermal growth factor receptor), ALK (anaplastic lymphoma kinase) and ROS1 genes. Some mutations can be treated with medicines known as targeted therapy, but others do not yet have a targeted therapy available.
Certain proteins found in some types of non-small cell lung cancer suggest that the cancer may respond to immunotherapy. These include proteins known as PD-1 and PD-L1.
Many people diagnosed with lung cancer have already stopped smoking, often years before, and some have never smoked at all. If you are a smoker, your doctors will advise you to stop smoking before you start treatment for lung cancer. This is because smoking may make the treatment less effective and side effects worse.
Quitting can be hard, especially if you're already feeling anxious about the cancer diagnosis, so it is important to seek support. This may include a combination of:
- counselling, either over the phone, online or face-to-face
- nicotine replacement therapy (patches, lozenges, gum, sprays or inhalers)
- medicines that reduce nicotine craving and withdrawalsymptoms.
To work out a plan for quitting, talk to your doctor, call Quitline 13 7848 or visit quitnow.gov.au.
If the tests described above show that you have lung cancer, further tests are done to see whether the cancer has spread to other parts of your body.
A PET (positron emission tomography) scan is a specialised imaging test available at most major hospitals. You will be asked to fast (not eat or drink) for a number of hours before the scan. A small amount of radioactive glucose solution will be injected into a vein, usually in your arm. You will need to sit quietly for 30–90 minutes while the glucose solution travels around your body, then you will lie on a table that moves through the scanning machine very slowly. Cancer cells take up more of the glucose solution than normal cells do, so they show up brighter on the scan.
You may also have a CT scan of the abdomen to check the liver; a bone scan; and a CT or MRI scan of the brain. For more information about these tests, talk to your doctor or call Cancer Council 13 11 20.
Staging lung cancer
The tests described above help your specialist work out how far the cancer has spread. This is known as staging, and it helps your health care team recommend the best treatment for you.
Non-small cell lung cancer and small cell lung cancer can both be staged using the TNM system. See below for more information about this staging system.
TNM stands for tumour-nodes-metastasis. Each letter is assigned a number (and sometimes also a letter) 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. The staging system for lung cancer is complex and often changes, so ask your doctor to explain how it applies to you.
Indicates the size of the tumour and the depth of any tumour invasion into the lung. Ranges from T1a (tumour is less than 1 cm) to T4 (tumour is more than 7 cm, or has grown into nearby structures, or there are two or more separate tumours in the same lobe of a lung).
Shows if the tumour has spread to nearby lymph nodes. Ranges from N0 (no spread) to N3 (cancer in lymph nodes on the opposite side of the chest, above the collarbone or at the top of the lung).
Shows if the tumour has spread to other parts of the body. Ranges from M0 (no spread to distant parts of the body) to M1c (cancer has spread and formed more than one tumour in distant parts of the body, e.g. liver, bone).
Lung cancer by stage
- Stages I and II: early lung cancer
- Stage III: locally advanced lung cancer
- Stage IV: advanced or metastatic lung cancer
"Two days after my 34th birthday, I woke up with a sore shoulder and arm. I didn't think too much of it because the pain went away quickly.
"After I felt a lump on my left collarbone, I mentioned it to my dad and brother because they're doctors. They said it was probably because I'd had a cough in the past few weeks but to get an ultrasound.
"After some further scans and tests, it was confirmed to be stage IV non-small cell lung cancer. I was devastated.
"When I first tell someone that I have lung cancer, the first thing most people say is "did you smoke?" While I think that people have the best intentions and it's human nature to want to find the cause of a problem, does it really matter whether I had smoked or not? I'm a never-smoker, but if I did smoke, even if it was just one cigarette, should I feel that somehow it's my fault?
"I want to reduce the stigma suffered by lung cancer patients and their families who are already going through so much. I use statistics to educate people and raise awareness. I explain that many other lifestyle choices are linked to cancer and that smoking causes other health conditions, such as cardiovascular diseases and other cancers. I let them know that one in three women diagnosed with lung cancer is a never-smoker such as myself.
"A lot of the people I've met with lung cancer say they're guarded about their diagnosis. One carer said she didn't tell anyone for three years that her spouse had lung cancer for fear of being stigmatised.
"There needs to be a lot more compassion. I think that taking away the stigma will lead to greater funding for research. I am feeling hopeful about my future. It's important to me to stay in the moment and appreciate what I have."
Tell your cancer story.
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 anyone to predict the exact course of the disease. Instead, your doctor can give you an idea about the general outlook for people with the same type and stage of 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
- other factors such as your age, fitness and overall health,
- and whether you're currently a smoker.
As in most types of cancer, the results of lung cancer treatment tend to be better when the cancer is found and treated early. However, new treatments such as targeted therapy and immunotherapy have been effective in some people with advanced lung cancer.
Key points about diagnosing lung cancer
The tests to diagnose lung cancer may include:
- chest x-ray
- CT scan of the chest
- biopsy – lab tests on a tissue sample removed from your chest by CT-guided lung biopsy, bronchoscopy, endobronchial ultrasound (EBUS), mediastinoscopy or thoracoscopy
- sputum cytology – lab tests on a sample of mucus from the lungs
- pleural tap – lab tests on a sample of fluid drained from the lungs.
Other tests can give more information about the cancer and help doctors work out whether it has spread. These tests can guide treatment and may include:
- molecular tests – lab tests on the biopsy sample to identify particular genetic mutations in the cancer
- PET scan to check for cancer in other parts of the body
- CT scan of the abdomen or brain
- bone scan
- MRI scan of the brain.
Staging and prognosis
The specialist will tell you the stage of the cancer, which describes how much cancer there is and whether it has spread. You may also wish to discuss the prognosis, which is the expected outcome for people with the same type and stage of cancer as you.
Expert content reviewers:
Dr Henry Marshall, Thoracic Physician, The University of Queensland Thoracic Research Centre, The Prince Charles Hospital, QLD; Dr Naveed Alam, Thoracic Surgeon, St Vincent's Melbourne and Epworth Richmond Hospitals, VIC; A/Prof Martin Borg, Radiation Oncologist, GenesisCare, SA; Dr Lisa Briggs, Consumer; Kirsten Mooney, Thoracic Cancer Nurse Coordinator, WA Cancer & Palliative Care Network, WA; Claire Mulvihill, Lung Cancer Support Nurse, Lung Foundation Australia; Caitriona Nienaber, 13 11 20 Consultant, Cancer Council WA; A/Prof Nick Pavlakis, President, Australasian Lung Cancer Trials Group, President Elect, Clinical Oncology Society of Australia, and Senior Staff Specialist, Department of Medical Oncology, Royal North Shore Hospital, NSW.