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Macmillan and Cancerbackup merged in 2008. Together we provide free, high quality information for people affected by cancer through our publications, website and phone service. Find out more|.
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This information is about secondary cancer in the lung. This describes the situation when cancer cells have spread to the lungs from a cancer that began elsewhere in the body.
The original cancer is described as a primary cancer, and when it spreads this is referred to as secondaries or metastases.
This information does not discuss primary lung cancer (cancer that started in the lung). We have separate information about primary lung cancer|.
The lungs are a pair of organs in the chest that are responsible for breathing. When you breathe in, air passes from your nose or mouth, through the windpipe (trachea) and into one of the two airways (bronchi) that enter the lungs. These airways divide to form smaller tubes, at the end of which are millions of tiny sacs.
It is here that oxygen is absorbed from the air and passes into the bloodstream to be circulated around the body. The lungs are surrounded by a protective lining that consists of two membranes called the pleura.
Structure of the lungs and pleura
View a large copy of the structure of the lungs and pleura image|
Cancer can develop in the lungs in two ways. It can start in the lung (primary lung cancer|) or it can spread there from a primary cancer elsewhere in the body. If a cancer spreads to the lungs from another part of the body, this is known as secondary or metastatic lung cancer.
Cancerous tumours are made up of millions of cells. Some of these cells may break away from the primary cancer and travel in the bloodstream or the lymphatic system to another part of the body, in this case the lungs. Although any type of cancer can spread to the lung, the most common types to spread to this area are cancers of the large bowel (colon and rectum)|, breast|, bladder|, testicle|, stomach|, gullet (oesophagus)|, kidney (renal)| and a type of skin cancer called malignant melanoma|.
The symptoms of a secondary lung cancer may be quite distressing, and can include:
Many of these symptoms are similar to those of a primary lung cancer. They are more commonly caused by conditions other than cancer, such as a chest infection, but you should see your doctor if you have any of these symptoms.
A doctor may suspect a secondary lung cancer if you've already been diagnosed with a cancer and you have some of these symptoms, particularly if they do not respond to other treatment such as antibiotics.
Sometimes, secondaries or metastases are found before a primary cancer has been diagnosed. Occasionally, it may not be possible to find the original cancer - this is called an 'unknown primary'|.
A number of tests may be done to diagnose a secondary lung cancer, including:
This may be taken to show the size and position of the cancer.
A CT scan takes a series of x-rays that build up a three-dimensional picture of the inside of the body. The scan is painless and takes 10–30 minutes. CT scans use a small amount of radiation, which will be very unlikely to harm you and will not harm anyone you come into contact with. You will be asked not to eat or drink for at least four hours before the scan.
You may be given a drink or injection of a dye, which allows particular areas to be seen more clearly. For a few minutes, this may make you feel hot all over. If you are allergic to iodine or have asthma you could have a more serious reaction to the injection, so it is important to let your doctor know beforehand.
Before the scan you may be asked to complete and sign a checklist to make sure that it’s safe for you.
Before having the scan, you’ll be asked to remove any metal belongings, including jewellery. Some people are given an injection of dye into a vein in the arm. This is called a contrast medium and can help the images from the scan to show up more clearly. During the test you will be asked to lie very still on a couch inside a long cylinder (tube) for about 30 minutes.
It is painless but can be slightly uncomfortable, and some people feel a bit claustrophobic during the scan. It’s also noisy, but you’ll be given earplugs or headphones. You'll be able to hear, and speak to, the person operating the scanner.
This uses low-dose radioactive sugar to measure the activity of cells in different parts of the body. A very small amount of a mildly radioactive substance is injected into a vein, usually in your arm. A scan is taken a couple of hours later. Areas of cancer are usually more active than surrounding tissue and show up on the scan.
Sometimes the doctors need to carry out a biopsy. This is usually done in the x-ray department, most commonly during a CT scan. A local anaesthetic is used to numb the area, then a needle is inserted to remove a small piece of tissue. The sample can then be examined under a microscope. The biopsy may be slightly uncomfortable but only takes a few minutes.
Secondary lung cancer may also cause fluid to collect in the space between the two membranes (the pleura) that surround the lungs. This is known as a pleural effusion|. If this happens, it may be possible to remove some of the fluid and examine it for cancer cells.
When the cancer cells are examined, the doctors can tell that it is a secondary lung cancer because the cells look like the cells from the original cancer. For example, if a stomach cancer has spread to the lungs, the cells would look like stomach cancer cells rather than lung cancer cells.
The treatment for a secondary lung cancer depends on the individual situation, including your general health and the type of primary cancer. Sometimes, a combination of treatments are used.
Chemotherapy| is commonly given to reduce and control secondary cancers in the lung. The type of chemotherapy you have will depend on whether you've had chemotherapy before and how long ago.
Hormonal therapy| is also commonly used to treat secondary cancers in the lung when they have developed from certain cancers, such as breast or prostate cancer|, that are responsive to hormonal treatments. The type of hormonal therapy you have will depend on which hormonal treatments you've already been given.
Surgery| to remove the secondary lung cancer may be possible for a small number of people. This may only be an option only if the primary cancer has been controlled and there is no evidence of the cancer having spread anywhere else in the body. It also requires the cancer to be affecting just one small part of the lungs, which is easy to get to, and not attached to important blood vessels or nerves.
You may have a short course of radiotherapy| to relieve some of the symptoms of the secondary lung cancer, such as pain|, breathlessness or coughing up blood (haemoptysis).
If the cancer is causing a blockage in the windpipe or one of the large airways, laser therapy may be used to burn the tumour out of the airway. This may relieve some of the symptoms, though it does not destroy the cancer completely.
If the cancer is causing pressure on structures close to the windpipe, a small tube called a stent may be inserted to hold the windpipe open. The stent can remain in the lung permanently and does not generally cause any problems.
A special form of internal radiotherapy (brachytherapy|) called endobronchial radiotherapy may be given when the tumour is blocking one of the airways. Using a flexible tube called a bronchoscope, a thin tube (catheter) containing radioactive material is placed close to the tumour. The radioactive material gives a dose of radiation to the tumour. It is left in place for a few minutes to give the treatment and then removed together with the catheter. Usually only one session of treatment is needed.
The symptoms of a secondary lung cancer can affect a person's day-to-day life and can be distressing.
It can help to note down your main symptoms so that when you see the doctor you can discuss each in turn.
This is a common and frightening problem that can affect all aspects of your life. The distress caused by being breathless| can be partly relieved by medication and activities such as muscle relaxation. Your GP can prescribe oxygen to ease your breathlessness.
Sometimes it isn't possible to drain the fluid as it can collect in a number of small pockets rather than in one place.
A pleural effusion can build up again, so a chemical may be inserted into the space between the pleura to try to prevent it from recurring. This procedure is called pleurodesis and occasionally it may be done surgically for better effect. However, this is more complicated and will only be suitable for patients who are otherwise very fit.
These can usually be relieved using medicines, which your doctor can prescribe.
People who are experiencing problems with breathing may have a fear of choking. However, this is very unlikely to happen.
It's not unusual to notice some streaks of blood in your phlegm if you have secondary lung cancer. If you notice larger amounts of blood, let your doctor know so they can plan specific treatment (such as radiotherapy) to control it.
Research into treatments for secondary cancers in the lung is ongoing and advances are being made. Cancer specialists use clinical trials| to assess new treatments. Before any trial takes place, an ethics committee must have approved it and agreed that the trial is in the interest of patients.
You may be asked to take part in a clinical trial. Your doctor will discuss the treatment with you so that you have a full understanding of the trial and what it involves. You may decide not to take part, or to withdraw from a trial, at any stage. You will then receive the best standard treatment.
Learning that your cancer has spread or come back may be even more devastating than hearing for the first time that you have cancer. You may have many different emotions|, including anger, resentment, guilt, anxiety and fear. These are all normal reactions, and are part of the process many people go through in trying to come to terms with their illness.
Everyone has their own way of coping with difficult situations; some people find it helpful to talk to family or friends, while others prefer to seek help from people outside their situation. Some people prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is available if you need it.
Our cancer support specialists| can give you details of counselling services in your area.
This section has been compiled using information from a number of reliable sources including:
For answers, support or just a chat, call the Macmillan Support Line free (Monday to Friday, 9am-8pm)
If you have any questions about cancer, need support or just want someone to talk to, ask Macmillan.