Lung cancer is one of the most common and serious types of cancer.
Around 44,500 people are
diagnosed with the condition every year in the UK.
There are usually no signs or symptoms in the early stages of lung
cancer, but many people with the condition eventually develop symptoms
including:
- a persistent cough
- coughing up blood
- persistent breathlessness
- unexplained tiredness and weight loss
- an ache or pain when breathing or coughing
You should see your GP if you have these symptoms.
Read more about the symptoms of lung cancer.
Types of lung cancer
Cancer that begins in the lungs is called primary lung cancer. Cancer
that spreads from the lungs to another place in the body is known as
secondary lung cancer. This page is about primary lung cancer.
There are two main types of primary lung cancer. These are classified by the type of cells in which the cancer starts. They are:
- non-small-cell lung cancer – the most common type, accounting for more than 80% of cases; can be either squamous cell carcinoma, adenocarcinoma or large-cell carcinoma
- small-cell lung cancer – a less common type that usually spreads faster than non-small-cell lung cancer
The type of lung cancer you have determines which treatments are recommended.
.
Diagnosing lung cancer
See your GP if you have symptoms of lung cancer, such as breathlessness or a persistent cough.
Your GP will ask about your general health and what symptoms you've
been experiencing. They may examine you and ask you to breathe into a
device called a spirometer, which measures how much air you breathe in and out.
You may be asked to have a blood test to rule out some of the possible causes of your symptoms, such as a chest infection.
In 2015, the National Institute for Health and Care Excellence (NICE)
published guidelines to help GPs recognise the signs and symptoms of
lung cancer and refer people for the right tests faster. To find out if
you should be referred for further tests for suspected lung cancer, read
the NICE 2015 guidelines on Suspected Cancer: Recognition and Referral.
Chest X-ray
A chest X-ray is usually the first test used to diagnose lung cancer. Most lung tumours show up on X-rays as a white-grey mass.
However, chest X-rays can't give a definitive diagnosis because they
often can't distinguish between cancer and other conditions, such as a
lung abscess (a collection of pus that forms in the lungs).
If your chest X-ray suggests you may have lung cancer, you should be
referred to a specialist (if you haven't already) in chest conditions
such as lung cancer. A specialist can carry out more tests to
investigate whether you have lung cancer and, if you do, what type it
is and how much it's spread.
CT scan
A computerised tomography (CT) scan
is usually carried out after a chest X-ray. A CT scan uses X-rays and a
computer to create detailed images of the inside of your body.
Before having a CT scan, you'll be given an injection of a contrast
medium. This is a liquid containing a dye that makes the lungs show up
more clearly on the scan. The scan is painless and takes 10-30 minutes
to complete.
PET-CT scan
A PET-CT scan (which stands for positron emission tomography-computerised tomography) may be carried out if the results of the CT scan show you have cancer at an early stage.
The PET-CT scan can show where there are active cancer cells. This can help with diagnosis and treatment.
Before having a PET-CT scan, you'll be injected with a slightly
radioactive material. You'll be asked to lie down on a table, which
slides into the PET scanner. The scan is painless and takes around 30-60
minutes.
Bronchoscopy and biopsy
If the CT scan shows there might be cancer in the central part of
your chest, you'll have a bronchoscopy. A bronchoscopy is a
procedure that allows a doctor or nurse to remove a small sample of
cells from inside your lungs.
During a bronchoscopy, a thin tube called a bronchoscope is used to examine your lungs and take a sample of cells (biopsy). The bronchoscope is passed through your mouth or nose, down your throat and into the airways of your lungs.
The procedure may be uncomfortable, but you'll be given a mild sedative beforehand to help you relax and a local anaesthetic to make your throat numb. The procedure is very quick and only takes a few minutes.
Other types of biopsy
If you're not able to have one of the biopsies described above, or
you've had one and the results weren't clear, you may be offered a
different type of biopsy. This may be a type of surgical biopsy such as a
thoracoscopy or a mediastinoscopy, or a biopsy carried out using a
needle inserted through your skin.
These types of biopsy are described below.
Percutaneous needle biopsy
A percutaneous needle biopsy involves removing a sample from a suspected tumour to test it at a laboratory for cancerous cells.
The doctor carrying out the biopsy will use a CT scanner to guide a
needle to the site of a suspected tumour through the skin. A local
anaesthetic is used to numb the surrounding skin, and the needle is
passed through your skin and into your lungs. The needle will then be
used to remove a sample of tissue for testing.
Thoracoscopy
A thoracoscopy is a procedure that allows the doctor to examine a
particular area of your chest and take tissue and fluid samples.
You're likely to need a general anaesthetic
before having a thoracoscopy. Two or three small cuts will be made in
your chest to pass a tube (similar to a bronchoscope) into your chest.
The doctor will use the tube to look inside your chest and take samples.
The samples will then be sent away for tests.
After a thoracoscopy, you may need to stay in hospital overnight while any further fluid in your lungs is drained out.
Mediastinoscopy
A mediastinoscopy allows the doctor to examine the area between your lungs at the centre of your chest (mediastinum).
For this test, you'll need to have a general anaesthetic and stay in
hospital for a couple of days. The doctor will make a small cut at the
bottom of your neck so they can pass a thin tube into your chest.
The tube has a camera at the end, which enables the doctor to see
inside your chest. They'll also be able to take samples of your cells
and lymph nodes at the same time. The lymph nodes are tested because
they're usually the first place that lung cancer spreads to.
Staging
Once the above tests have been completed, it should be possible to
work out what stage your cancer is, what this means for your treatment
and whether it's possible to completely cure the cancer.
Non-small-cell lung cancer
Non-small-cell lung cancer (the most common type) usually spreads
more slowly than small-cell lung cancer and responds differently to
treatment.
The stages of non-small-cell lung cancer are outlined below.
Stage 1
The cancer is contained within the lung and hasn't spread to nearby
lymph nodes. Stage 1 can also be divided into two sub-stages:
- stage 1A – the tumour is less than 3cm in size (1.2 inches)
- stage 1B – the tumour is 3-5cm (1.2-2 inches)
Stage 2
Stage 2 is divided into two sub-stages: 2A and 2B.
In stage 2A lung cancer, either:
- the tumour is 5-7cm
- the tumour is less than 5cm and cancerous cells have spread to nearby lymph nodes
In stage 2B lung cancer, either:
- the tumour is larger than 7cm
- the tumour is 5-7cm and cancerous cells have spread to nearby lymph nodes
- the cancer hasn't spread to lymph nodes, but has spread to surrounding muscles or tissue
- the cancer has spread to one of the main airways (bronchus)
- the cancer has caused the lung to collapse
- there are multiple small tumours in the lung
Stage 3
Stage 3 is divided into two sub-stages: 3A and 3B.
In stage 3A lung cancer, the cancer has either spread to the lymph
nodes in the middle of the chest or into the surrounding tissue. This
can be:
- the covering of the lung (the pleura)
- the chest wall
- the middle of the chest
- other lymph nodes near the affected lung
In stage 3B lung cancer, the cancer has spread to either of the following:
- lymph nodes on either side of the chest, above the collarbones
- another important part of the body, such as the gullet (oesophagus), windpipe (trachea), heart or into a main blood vessel
Stage 4
In stage 4 lung cancer, the cancer has either spread to both lungs or
to another part of the body (such as the bones, liver or brain), or the
cancer has caused fluid-containing cancer cells to build up around your
heart or lungs.
Small-cell lung cancer
Small-cell lung cancer is less common than non-small-cell lung
cancer. The cancerous cells responsible for the condition are smaller in
size when examined under a microscope than the cells that cause
non-small-cell lung cancer.
Small-cell lung cancer only has two possible stages:
- limited disease – the cancer has not spread beyond the lung
- extensive disease – the cancer has spread beyond the lung
Who's affected
Lung cancer mainly affects older people. It's rare in people younger
than 40, and the rates of lung cancer rise sharply with age. Lung cancer
is most commonly diagnosed in people aged 70-74.
Although people who have never smoked can develop lung cancer,
smoking is the main cause (accounting for over 85% of cases). This is
because smoking involves regularly inhaling a number of different toxic
substances.
Causes of lung cancer
Most cases of lung cancer are caused by smoking, although people who have never smoked can also develop the condition.Smoking
Smoking cigarettes is the single biggest risk factor for lung cancer. It's responsible for more than 85% of all cases.Tobacco smoke contains more than 60 different toxic substances, which can lead to the development of cancer. These substances are known to be carcinogenic (cancer-producing).
If you smoke more than 25 cigarettes a day, you are 25 times more likely to get lung cancer than a non-smoker.
While smoking cigarettes is the biggest risk factor, using other types of tobacco products can also increase your risk of developing lung cancer and other types of cancer, such as oesophageal cancer and mouth cancer. These products include:
- cigars
- pipe tobacco
- snuff (a powdered form of tobacco)
- chewing tobacco
It's been estimated that smoking four joints (homemade cigarettes mixed with cannabis) may be as damaging to the lungs as smoking 20 cigarettes.
Even smoking cannabis without mixing it with tobacco is potentially dangerous. This is because cannabis also contains substances that can cause cancer.
Passive smoking
If you don't smoke, frequent exposure to other people’s tobacco smoke (passive smoking) can increase your risk of developing lung cancer.For example, research has found that non-smoking women who share their house with a smoking partner are 25% more likely to develop lung cancer than non-smoking women who live with a non-smoking partner.
Radon
Radon is a naturally occurring radioactive gas that comes from tiny amounts of uranium present in all rocks and soils. It can sometimes be found in buildings.If radon is breathed in, it can damage your lungs, particularly if you're a smoker. Radon is estimated to be responsible for about 3% of all lung cancer deaths in England.
Occupational exposure and pollution
Exposure to certain chemicals and substances used in several occupations and industries has been linked to a slightly higher risk of developing lung cancer. These chemicals and substances include:- arsenic
- asbestos
- beryllium
- cadmium
- coal and coke fumes
- silica
- nickel
Research also suggests that being exposed to large amounts of diesel fumes for many years may increase your risk of developing lung cancer by up to 50%. One study has shown that your risk of developing lung cancer increases by about a third if you live in an area with high levels of nitrogen oxide gases (mostly produced by cars and other vehicles)
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