Lung cancer is a type of cancer that begins in the lungs. If left untreated, it can spread beyond the lungs into nearby tissue or other parts of the body. Smoking is the main cause of lung cancer.
- Lung cancer is the 5th most common type of cancer in New Zealand.
- The vast majority (80–90%) of cases of lung cancer are due to long-term exposure to tobacco smoke
- Sadly, it is often found at a late stage when it has already spread to other parts of the body.
- As a result, lung cancer is the most common cause of death from cancer for New Zealand men, and the second most common for women.
- The best option is to find lung cancer early by looking out for symptoms, especially in smokers or past smokers and see a doctor straight away.
Smoking is the single main avoidable cause of lung cancer. It is not known why one smoker develops lung cancer and another does not. Up to 90% of lung cancer is caused by smoking.
Lung cancer occurs most often in adults between the ages of 40 and 70 who have smoked cigarettes for at least 20 years. They are also likely to have started smoking as teenagers.
Second-hand smoking (passive smoking) may also cause lung cancer. However, as with many cancers, we do not know the cause in all cases.
Occupational exposure to asbestos is associated with an increased risk of asbestosis, mesothelioma (a rare cancer of the pleural membranes on the surface of the lungs and lung cancer. For people with asbestosis, their risk of developing lung cancer is doubled. If the person also smokes, then the risk is increased.
Other occupational exposures that possibly are associated with lung cancer include contact with the processing of steel, nickel, chrome and coal gas. Exposure to radiation causes an increased risk of all cancers, including lung cancer.
Miners of uranium, fluorspar and haematite may be exposed to radiation by breathing air contaminated with radon gas.
Some people have no symptoms, but learn they have lung cancer when it shows up as a mass or lump on a routine chest x-ray. Others realise something is wrong when new symptoms appear or a bout of bronchitis fails to get better quickly.
The most common symptoms of lung cancer are:
- a cough that does not go away
- repeated bouts of pneumonia or bronchitis
- shortness of breath
- noisy breathing
- pain in the chest and upper back area
- coughing up blood.
In the later stages of lung cancer, people may experience fatigue, loss of weight, extreme shortness of breath, hoarseness, difficulty in swallowing, facial swelling and back pain.
There may also be symptoms that seem unrelated to the lungs. These may be caused by the spread of a lung cancer to other parts of the body.
In diagnosing lung cancer your doctor will consider your symptoms, ask about your previous and current health, smoking and work history, and do a physical examination. You may then have one or a series of tests which can include a chest x-ray, types of scans and biopsies.
- Chest x-ray – an x-ray of the chest can sometimes identify tumours as small as one centimetre in diameter. However, tumours can easily be hidden by surrounding areas of infection and are not always obvious on x-ray.
- Sputum cytology – the sputum cytology test is an examination of sputum (phlegm/spit which you cough up from your lungs) under a microscope to check for abnormal cells. You will be asked to collect early-morning samples for several days. To do this you will need to cough deeply to bring up liquid from your lungs. You can do this at home, storing the sample in the fridge before taking it to the laboratory. A negative sputum test does not rule out cancer.
- Bronchoscopy – an instrument called a bronchoscope is often used to look down inside your airways and take a sample of any abnormal looking tissue.
- CT Scan – a computerised tomography (CT) scan can be used to assess a tumour more accurately. It can also assess whether lymph nodes are enlarged, or whether other organs are affected. The scan will usually look at your thorax and upper abdomen.
- Fine-needle aspiration – to do this, the doctor inserts a needle between the ribs into the tumour so a sample can be taken. This is nearly always done with the help of a CT scan in the x-ray department.
- Thoracentesis – this procedure also uses a fine needle. Instead of the doctor sampling the tumour, they will draw fluid from the pleural space (a space between the two layers of the pleura – which are membranes that line the chest wall and cover the lungs) to check for cancer cells.
- Mediastinoscopy – this is a surgical procedure for examining and taking a biopsy of lymph nodes in the mediastinum (the area in the chest cavity between the lungs, that contains the heart and large blood vessels, the oesophagus, the trachea, and many lymph nodes). This test requires a general anaesthetic and a short stay in hospital. The doctor inserts the viewing scope through a small cut (incision) made above the sternum (the breast-bone).
Further tests that are sometimes used
- Bone scans – if lung cancer is confirmed, a bone scan can help show whether lung cancer has spread to the bones.
- Positron emission tomography (PET) scans are being increasingly used before treatment. Before a PET scan a person is injected with a glucose solution (FDG) containing a very small amount of radioactive material. The scanner can ‘see’ the radioactive substance. Damaged or cancerous cells may show up as areas where the glucose is being taken up. You may have both a PET scan and a CT scan during your appointment.
- Other tests: blood tests and breathing tests. If surgery is contemplated, it is very important to measure your breathing.
The tests described above show whether you have cancer, its size and whether the cancer cells have spread to other parts of your body.
Types of lung cancer
There are two ways you will hear lung cancer referred to: non-small cell lung cancer and small-cell lung cancer.
Non-small cell lung cancer is divided into four stages:
- Stage 1 – small and localised.
- Stage 2 or 3 – has spread into surrounding structures, such as lymph nodes and the chest wall or both.
- Stage 4 – has spread to other parts of the body, such as the liver, bones or brain.
Small-cell lung cancer is divided into two stages:
- Limited disease – the cancer cells can be seen only in one lung, in nearby lymph nodes, or in fluid around the lungs (known as pleural effusion).
- Extensive disease – it is clear that the cancer has spread outside the lung, within the chest area, or to other parts of the body.
More on types of lung cancer
The main treatments for lung cancer are surgery, radiation treatment and chemotherapy. The choice of treatment will depend on:
- the type of lung cancer
- whether the cancer has spread beyond the lung,
- how well your lungs are functioning
- your general health.
The aim of treatment is to keep you as well and symptom-free as possible, even if your cancer cannot be cured. Your doctors will consider your general state of health and personal choices when determining treatment options.
Surgery for non-small cell lung cancer
Surgery is the first treatment considered for non-small cell lung cancer. This is only possible if:
- the cancer has not spread beyond the lung and
- your health (apart from the cancer) is reasonably good and
- your breathing capacity is adequate.
The most common operation, called a lobectomy, removes the affected part of the lung. Occasionally, the whole lung needs to be removed and this is called a pneumonectomy.
In patients with reduced breathing, smaller parts of the lung may be removed to balance the impact on your breathing.
Chemotherapy is the treatment of cancer using anti-cancer (cytotoxic) drugs. The aim of chemotherapy is to kill the cancer cells while doing as little damage as possible to normal cells. It is the main form of treatment for small-cell lung cancer.
Chemotherapy is usually given in an outpatient clinic, and this treatment is spread over weeks and months. Although most chemotherapy is given as an intravenous infusion (IV drip), some types can be given by tablet.
Most of the side effects of chemotherapy are temporary and go away after treatment or within a few months of stopping. Talk with your specialist team about what how to manage these and what to watch out for.
If you develop a fever (have a temperature of 38 degrees Celsius or over), or feel unwell, even with a normal temperature, do not wait to see what happens. Phone your cancer treatment centre, oncologist, oncology nurse or hospital immediately for advice.
Radiation treatment uses high-energy radiation to destroy cancer cells or prevent them from reproducing. Radiation treatment only affects the part of the body at which the beam(s) are aimed, so is very localised.
About half of all people with cancer need radiation treatment at some point in their illness. For some types of cancer this is the main treatment. It might be used in combination with surgery, chemotherapy or hormone therapy.
Radiation treatment may be given as a single one-off dose, or in a course of up to 30 to 35 treatments depending on individual circumstances. For longer courses, radiation is usually given daily for 4 or 5 days a week, but not usually over weekends.
Each treatment session usually lasts about 10 to 15 minutes. You will see a doctor once a week during treatment to check on your progress. Additional blood tests, x-rays or scans may be required to help with this.
Emotions & cancer English/Māori Cancer Society, NZ, 2020
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