Tests for pancreatic cancer

To help make the diagnosis, you'll probably have a number of tests. After a diagnosis is made, more tests may be needed to find out about the size and position of the cancer, and whether it has spread to other parts of the body. The results will help your doctor to decide on the best treatment for you. 

While tests are useful, no one test can tell the whole story. Even the most modern scans can’t always pick up tiny areas of cancer. Occasionally, other medical conditions can cause similar results, making it difficult to decide what is and is not cancer. Doctors often have to piece together information from different tests and examinations, along with your symptoms and medical history, and then put all this information in context.

Usually, only tests that give the most helpful information about the illness are used. The following tests are often used to diagnose cancer of the pancreas:

• blood tests
• CT scan (computerised tomography) – a series of x-rays that builds up a three-dimensional picture of the inside of the body
• ultrasound – uses sound waves to look at organs such as the pancreas and liver
• MRI scan – uses magnetic fields to build up a series of cross-sectional pictures of the body
• ERCP (endoscopic retrograde cholangio pancreatography) – a thin tube (endoscope) is passed through your mouth and stomach to take an x-ray
• EUS (endoscopic ultrasound) – sometimes used instead of an ERCP
• biopsy – some cells are removed from the abnormal area and examined under a microscope
• laparoscopy - a small operation done under general anaesthetic to see whether further surgery will be possible.

What the tests involve

Blood tests

Many cancers of the pancreas produce a substance called CA 19-9, which can be measured in the blood. CA 19-9 is known as a tumour marker. Measuring the level of CA 19-9 in the blood can help to diagnose a cancer of the pancreas, and also to see how it responds to treatment. This test is not enough on its own to make a diagnosis, and needs to be used alongside other tests such as scans.

Blood is usually taken from a vein, generally in the arm at the elbow. You may have a tight band called a tourniquet put around your arm first to make it easier to draw the blood, and a small needle is then inserted into the vein and the blood drawn off. Many people don’t like to see needles or worry about seeing blood – tell the person taking the blood beforehand if you are worried about having blood taken. It helps to be seated or lying down  – if you do feel faint, tell the person straight away. After the test, you’ll have a piece of cotton wool placed over the area, and you may be asked to press on it for a short time (about a minute) before a plaster is applied. 

CT scan

A CT (computerised tomography) scan takes a series of x-rays which builds up a three-dimensional picture of the inside of the body. The scan is painless, but takes from 10 to 30 minutes. CT scans use a small amount of radiation, which is very unlikely to harm you and will not harm anyone you come into contact with. You’ll 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. If you are allergic to iodine or have asthma you could have a more serious reaction to the injection, so it’s important to let your doctor know beforehand.

CT scans can be used to guide a biopsy, in which a small amount of tissue is taken for examination under a microscope. You’ll be told if this is planned.

You will probably be able to go home as soon as the scan is over.

Ultrasound scan

Ultrasound uses sound waves to look at internal organs, such as the pancreas and the liver. You’ll usually be asked not to eat or drink anything for at least six hours before the test.

Once you are lying comfortably on your back, a gel is spread on to the area to be scanned. A small device that produces sound waves is passed over the area. The sound waves are then converted into a picture by a computer. This test only takes a few minutes.

As with CT scans, an ultrasound can be used to guide a biopsy, in which tissue is taken for examination under a microscope.

MRI (magnetic resonance imaging) scan

This test is similar to a CT scan but uses magnetism instead of x-rays to build up a detailed picture of areas of your body. Before the scan you may be asked to complete and sign a checklist. This is to make sure that it’s safe for you to have an MRI scan (because the scanner is a powerful magnet). 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 have 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 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, 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 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 will be able to hear, and speak to, the person operating the scanner.

ERCP

ERCP (endoscopic retrograde cholangio pancreatography) enables the doctor to take an x-ray picture of the pancreatic duct and the bile duct. The bile duct can be unblocked during this procedure| if necessary.

Before the test, you will be asked not to eat or drink anything for about six hours so that the stomach and small bowel (duodenum) are empty. You will be given an injection to help you to relax and some local anaesthetic will be sprayed on to the back of your throat. The doctor will then pass a thin, flexible tube, known as an endoscope, into your mouth, through your stomach and into the duodenum.

Looking down the endoscope, the doctor can find the opening where the bile duct and the pancreatic duct drain into the duodenum. A dye that can be seen on x-ray is then injected into these ducts to show up any abnormalities or any blockage of the duct.

You’ll usually be given an injection of antibiotics before the test, to prevent any infection.

Most people are ready to go home a couple of hours after their test. It’s a good idea to arrange for someone to collect you from the hospital as you shouldn’t drive for several hours after a sedative.

EUS (endoscopic ultrasound)

A newer test that is sometimes used instead of an ERCP, is an endoscopic ultrasound (EUS). This is a similar procedure to an ERCP, but involves an ultrasound probe being passed down the endoscope, to take an ultrasound scan of the pancreas and surrounding organs. Ultrasound uses high-frequency sound waves to build up a picture. Biopsies can also be taken during an EUS.

Biopsy

If your doctor strongly suspects that you have cancer of the pancreas, they’ll usually suggest that you have a biopsy to confirm the diagnosis. This involves removing some cells or a small piece of tissue, from the tumour, to be looked at under a microscope.

A biopsy can be taken in a number of ways. It may be possible to insert a needle through the skin of the abdomen to take a small piece of tissue, using an ultrasound or CT scan for guidance. You’ll be given an injection of local anaesthetic to numb the area so that you feel little or no pain from the insertion of the needle.

Another way is to take some cells during an ERCP or an EUS.

Laparoscopy

This test involves a small operation done under a general anaesthetic and will mean a short stay in hospital. It allows the doctor to look at the area of the pancreas and see whether an operation will be possible.

The doctor makes a small cut (about 2cm/1inch) in the skin and muscle near the navel and carefully inserts a thin, fibre-optic tube (laparoscope) into your abdomen. The doctor can then examine the area and take a sample of tissue (biopsy) for examination under the microscope. Sometimes gas is pumped into the abdomen to make it easier for the doctor to see the pancreas. The gas will not harm you and it will gradually disappear after the laparoscopy.

If the above tests do not give a definite diagnosis, an operation to look inside the abdomen (called a laparotomy) may be done under a general anaesthetic. It’s rare for a laparotomy to be needed as most people can have a laparoscopy.

ERCP, biopsy and laparoscopy can cause problems for some people. Your specialist should discuss any possible risks with you before you have any of these procedures.