How is Cancer Diagnosed ?
What tests are used?
The main tests to diagnose cancer are listed below. Some of these tests may also help to show the stage of the cancer. Most of the scans are done in the X-ray department of the hospital. Surgery is done in the operating theatre.
Barium X-ray
A barium X-ray outlines the part of your gullet, stomach or bowel that needs checking and can show up any abnormal changes.
Barium Enema
A barium enema is a special X-ray of the bowel. To get good X-ray pictures your bowel must be empty. For the test, a nurse will ask you to lie on your side on a special table.
A thin rubber tube will then be gently put into your back passage. The barium mixture will be poured through the tube into your bowel. You will then be asked to hold on to the barium mixture until the X-ray is finished.
Barium Swallow
A barium swallow is a special X-ray of the gullet (oesophagus). For this test, you cannot eat or drink for 6 hours beforehand. In the X-ray department you will be asked to drink a white chalky liquid that contains barium. The barium will flow down your oesophagus and the X-ray will be taken. A barium swallow lasts about 15 minutes and does not hurt.
Biopsy
During certain tests your doctor can take tissue samples from the affected area. These can then be looked at carefully under a microscope in the laboratory. This is known as a biopsy. It can find out if cancer cells are present. A biopsy can be done during the following tests: endoscopy, bone marrow tests and surgery.
Bone marrow tests
Bone marrow tests are done to diagnose leukaemia or myeloma.
In this test a tiny sample of your bone or bone marrow is looked at under a microscope. If a sample of bone marrow cells is taken, it is called an aspirate. If solid bone is taken, it is a trephine biopsy. Usually the sample is taken from the hipbone or sometimes the breastbone.
Before the test you will be given a local anaesthetic to numb the area. A needle is then passed gently through your skin into the bone marrow. A tiny sample of the bone marrow is then drawn off using a syringe. These cells will then be looked at under a microscope in the laboratory.
The test takes about 15 minutes and you will feel a little discomfort for a short while.
Bone scan
Bone scans are very sensitive and can find cancer cells before they show up on an X-ray. For this test, a very small amount of a mildly radioactive substance is injected into a vein, usually in your arm.
A scan is then taken of all the bones in your body. Because abnormal bone absorbs more of the radioactive substance than normal bone, it can show up on the scan.
After you get the injection, you must wait for up to 3 hours before the scan can be taken. The amount of radioactivity used in these scans is very low and safe. It disappears from your body within a few hours.
CT scan
This is a special type of X-ray that builds up a picture of the tissues inside your body.
The CT scan can look at any part of your body. This includes your brain, lung, bowel, prostate, etc.For some CT scans you cannot eat or drink for 4 hours beforehand. For others, you may be given a special drink that helps to show up certain parts of your body on the scan. The test does not hurt and most people can go home afterwards.
Endoscopy
This type of test involves putting a thin tube into a part of your body. The tube has a light and camera at one end so that your doctor can see the tissues clearly. You must fast for this test beforehand. If your bowel is being tested, it must be empty so that your doctor can see the lining of the bowel clearly. Depending on the part of your body being tested, you may be given a light sedative to relax you beforehand.Some of the different types of endoscopy are:
- An oesophagoscopy looks at your gullet (oesophagus)
- A gastroscopy looks at your stomach
- A colonoscopy looks at your large bowel
- A sigmoidoscopy looks at the lower end of your bowel
- A proctoscopy looks at your back passage (rectum)
- A laryngoscopy look at your larynx (voicebox)
- A bronchoscopy looks at your lung airways
- A mediastinoscopy looks at the space behind your breastbone between your two lungs
- A cystoscopy looks at your bladder.
During an endoscopy test, your doctor can take samples of your tissues (biopsy) and look at them under a microscope in the laboratory.
Lumbar puncture
If your doctor suspects a brain cancer or if a cancer has spread to the brain, he or she will do a lumbar puncture. In this test a sample of cerebrospinal fluid is taken.
This fluid fills the spaces in and around your brain and spinal cord. Usually this test is done under local anaesthetic. You must lie on your side while your doctor removes the fluid with a thin needle. In all, the test lasts about 30 minutes.
The fluid is tested in the laboratory for signs of cancer or other conditions. Afterwards you must lie flat for several hours to prevent getting a headache.
MRI scan
This is a special scan that uses magnetic energy to build up a picture of the tissues inside your body. The MRI scan can look at any part of your body. This includes your brain, brain, lung, bowel, prostate, etc.
You may get an injection beforehand to show up certain areas of your body.
During the scan you cannot wear any metal jewellery or hair clips or prosthesis. Those who have certain medical devices in their body, like a pacemaker or metal pin, are not suitable for the test. If you have a nicotine patch or other drug patch you may be asked to remove it to prevent a skin burn. The test itself does not hurt and you can go home afterwards.
PET scan
This scan is a positron emission tomography (PET). It can give your doctor more information about cancer if found in your body. PET uses a low dose of radioactive sugar to measure the activity in your cells. This sugar is first injected into your arm and travels to all the cells in your body. Because cancer cells absorb large amounts of the sugar, there will be more radioactivity where the cancer cells are found.
After an hour, the scan is taken and can show if the cancer has spread to other tissues and organs. Before the test, you may have to fast for a few hours. The scan itself may take up to 1 hour. PET is safe to use and there are no side-effects.
Surgery
In some cases cancer can only be diagnosed by an operation. Depending on the area of the body affected, you may need an operation so that your doctor can take a sample of your tissue. For example, this could be a lung or brain biopsy. A skin biopsy can be done under local anaesthetic.
Sometimes an operation is needed to diagnose cancer in the area stretching from below your chest to your hipbones (abdomen and pelvis). This operation is called a laparotomy. A long cut is made near your stomach area so that your doctor can see your organs. Your doctor will explain this operation in detail to you.
If your doctor wants to check your ovaries or other nearby organs, he or she may decide to do a laparoscopy. This is a small operation done in theatre under a general anaesthetic. Just before going to theatre, you may be given a sedative to make you feel more relaxed. While you are asleep, your doctor makes a small cut in your lower abdomen near your belly button.
A small thin telescope called a laparoscope is then put in through the cut. By looking through the laparoscope your doctor can see your organs and take a small sample of tissue (biopsy) to check it.
During the operation, carbon dioxide gas is put into your abdomen. This may give you uncomfortable wind afterwards or shoulder pains for about 3 or 4 days. Afterwards, you will have one or two stitches at the wound site. Most people are ready to go home as soon as the effects of the anaesthetic have worn off.
Ultrasound scan
In this test, a picture is built up of the tissues inside your body using sound waves. Any part of your body can be scanned. Usually you are asked to lie on your back and a gel is spread over the area to be scanned. A small device like a microphone is then used to take the scan. This device makes sound waves that are changed into a picture on a computer. The test does not hurt and only takes about 10 minutes. You can go home afterwards.
After the tests
It may take about a week or longer for all the test results to come back. This can be an anxious time for you. It may help to talk things over with a family member or close friend. You can also call the National Cancer Helpline to speak to one of our specially trained nurses.
Cancer Information Service
Freefone 1800 200 700
(Monday–Thursday 9am-7pm;Friday 9am–5pm)
For more details on the tests needed to diagnose each cancer, visit the Types of Cancer section of this website.
During your cancer treatment you may also have some of above tests done. Your doctor will explain why you need them at that time. Once your treatment is over, some of the tests may be part of your follow-up too.
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