How secondary bone cancer is diagnosed
If your doctor thinks you may have a cancer that has spread to the bones, they will arrange for you to have some of the following tests and investigations.
A blood test may be done to check your general health and the level of calcium in your blood.
You may have a chest x-ray to check whether the cancer has spread to your lungs.
This is a simple x-ray that can show up changes in the bone and may show that a secondary bone cancer is present.
Not all secondary bone cancers can be seen on an x-ray.
This is a more sensitive test than an x-ray and shows up any abnormal areas of bone more clearly. A small amount of a mildly radioactive substance is injected into a vein, usually in your arm. Abnormal bone absorbs more radioactivity than normal bone, so these areas are highlighted and picked up by the scanner as ‘hot spots’. You’ll probably have to wait 2-3 hours between having the injection and the scan itself, so you may like to take a magazine or book with you to pass the time. The scan itself may take up to an hour.
Even if an abnormality is detected on the bone scan, it isn’t always clear whether it’s caused by cancer or by another condition such as arthritis. Sometimes a CT or MRI scan (see below) may be needed to help the doctors decide whether the changes seen on a bone scan are caused by secondary bone cancer or another condition.
The level of radioactivity used in this type of scan is very small and shouldn’t cause any harm. But you’ll be advised to avoid close contact with pregnant women or young children for a few hours after the scan.
CT (computerised tomography) scan
Back to top
A CT scan (see illustration below) takes a series of x-rays, which build up a three-dimensional picture of the inside of the body. The scan takes 10-30 minutes and is painless.
It uses a small amount of radiation, which is very unlikely to harm you and will not harm anyone you come into contact with.
You may 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. This may make you feel hot all over for a few minutes. It’s important to let your doctor know if you are allergic to iodine or have asthma, because you could have a more serious reaction to the injection.
You’ll probably be able to go home as soon as the scan is over.
MRI (magnetic resonance imaging) scan
Back to top
This test uses magnetism to build up a detailed picture of areas of your body. The scanner is a powerful magnet, so you will be asked to complete and sign a checklist to make sure it’s safe for you. The checklist asks about any metal implants you may have, for example a pacemaker, surgical clips, bone pins, etc.
You should also tell your doctor if you’ve ever worked with metal or in the metal industry as very tiny fragments of metal can sometimes lodge in the body. If you do have any metal in your body it’s likely that you won’t be able to have an MRI scan. In this situation another type of scan can be used.
Before 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, which doesn’t usually cause discomfort. This is called a contrast medium and can help the images from the scan to show up more clearly.
During the test you’ll lie very still on a couch inside a long cylinder (tube) for about 30 minutes. It’s painless but can be slightly uncomfortable, and some people feel a bit claustrophobic. It’s also noisy, but you’ll be given earplugs or headphones. You can hear, and speak to, the person operating the scanner.
PET (positron emission tomography) scan
Back to top
A PET scan uses low-dose radioactive glucose (a type of 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 then taken a couple of hours later. Cancer cells are usually more active than surrounding tissue, and show up on the scan. You should be able to go home as soon as the scan is over.
Not all hospitals have PET scanners, so if you need one you may have to travel to another hospital.
Occasionally, the doctors may still not be sure what’s causing the abnormality in the bone, for example if there’s only one abnormal spot identified in the bone. If this happens, you may need to have a small sample of cells taken from the affected bone (a biopsy). Bone is extremely hard, and the piece that is removed has to be softened so it can be examined under a microscope. The softening process takes several days, so you may have to wait 10-14 days for the results of the biopsy.
A biopsy can be carried out in either of the following ways:
This type of biopsy may be done during a CT scan. The scan is used to guide the doctor to the right place for taking the biopsy.
Before the biopsy is done, a local anaesthetic will be injected to numb the area. A needle is then passed through the skin into the bone and a small piece of the bone is taken. This part of the test can be painful. If you’re feeling very anxious, you may be given a sedative to help you relax.
This procedure doesn’t take very long, and you may have it as an outpatient and be able to go home afterwards. If the sample is taken from your back, you may need to stay in hospital overnight. You’re likely to be sore for a few days after the test. Your doctor will prescribe painkillers for you if you need them.
For this test, a small piece of bone is removed while you’re under a general anaesthetic. A small cut (incision) will be made in the skin above the affected bone so that the biopsy can be taken.
You’ll have a couple of stitches to close the wound and it will be covered with a dressing. The stitches will need to be removed after about 10-14 days, which the nurses will arrange for you.
An open biopsy takes about 30-60 minutes. You may have to stay in hospital overnight. After the biopsy, you’re likely to be sore for up to a week, so your doctor may give you some painkillers.
Diagnosing the primary cancer
Back to top
Occasionally, a secondary bone cancer is found before the primary cancer is diagnosed.
If this happens, your doctor may arrange for you to have tests to find out where the primary cancer is. For example, your doctor may ask you to have a:
mammogram to look for primary cancer in the breast
chest x-ray and CT scan to check for lung cancer
CT or ultrasound scan of the abdomen and pelvis to look for kidney cancer
prostate ultrasound and a blood sample taken to check for prostate cancer.
Waiting for test results
Back to top
Waiting for test results can be a difficult time. It may take from a few days to a couple of weeks for the results of your tests to be ready. You may find it helpful to talk with your partner, family or a close friend. Your specialist nurse or one of the organisations listed on our database can also provide support.
You can also talk things over with one of our cancer support specialists.