Diagnosis

Doctors use many tests to diagnose cancer and determine if it has metastasized. Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has metastasized. Your doctor may consider these factors when choosing a diagnostic test:

• Age and medical condition
  
  
• The type of cancer suspected
  
  
• Severity of symptoms
  
  
• Previous test results

If a doctor suspects that a person has pancreatic cancer, he or she will first ask about the person's medical history and examine the person to look for signs of the disease. The following tests may be used to diagnose pancreatic cancer:

Physical examination. The doctor will examine the skin and eyes to see if they are yellow, which is a sign of jaundice. Jaundice can result from a tumor at the head of the pancreas obstructing normal flow of bile (a substance produced in the liver) into the small intestine. The doctor will also feel the abdomen for changes caused by the cancer, although the pancreas itself, located in the back of the upper abdomen, is rarely palpable, meaning the doctor cannot feel it. The presence of ascites (an abnormal buildup of fluid in the abdomen) may be another sign of cancer.

Laboratory tests. The doctor may take samples of blood to check for abnormal levels of bilirubin and other substances. Bilirubin is a chemical that may reach high levels in patients with pancreatic cancer due to blockage of the common bile duct by a tumor. There are many other non-cancerous causes of an elevated bilirubin level, such as hepatitis, gall stones, or mononucleosis. CA 19-9 is a tumor marker (substances in the body that may be found at higher levels if cancer is present) that can be measured in the blood, and is frequently elevated in individuals with pancreatic cancer. An elevated CA 19-9 test by itself should not be used to make the diagnosis of pancreatic cancer, as CA 19-9 can be elevated in other, noncancerous conditions as well (such as pancreatitis, cirrhosis of the liver, and blockage of the common bile duct).

Imaging procedures allow doctors to determine where the cancer is located and whether it has spread from the pancreas to other areas of the body. However, pancreatic cancer often does not develop as a single large tumor mass, and therefore can sometimes be difficult to see on imaging tests.

Computed tomography (CT or CAT) scan. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. A contrast medium (a special dye) is usually injected into a patient’s vein to provide better detail.

Ultrasound. An ultrasound uses sound waves to create a picture of the internal organs. There are two types of ultrasound devices: transabdominal and endoscopic.

• A transabdominal ultrasound device is placed on the outside of the abdomen and is slowly moved around by the doctor to produce an image of the pancreas and surrounding structures.
  
  
• The endoscopic ultrasound (EUS) device consists of a thin, lighted tube that is passed through the patient's mouth and stomach and down into the small intestine in order to take a picture of the pancreas. This procedure is very specialized and requires a gastroenterologist (a doctor who specializes in the function and disorders of the gastrointestinal tract, including stomach, intestines, and associated organs) who has special training in this area. It is generally done under sedation, so the patient sleeps through the procedure.

Endoscopic retrograde cholangiopancreatography (ERCP). In this procedure performed by a gastroenterologist, an endoscope (a thin, lighted tube) is passed into the small intestine through the mouth and stomach. A catheter (smaller tube) is passed through the endoscope and into the bile ducts and pancreatic ducts. Dye is injected into the ducts, and the doctor then takes x-rays that can show whether a duct is compressed or narrowed. Often, a plastic or metal stent can be placed across the obstructed bile duct during ERCP to help relieve any jaundice. Brushings of the tissue, which means obtaining samples of the tissue during this procedure, sometimes help confirm the diagnosis of cancer. The patient is lightly sedated during this procedure.

Percutaneous transhepatic cholangiography (PTC). In this x-ray procedure, a thin needle is inserted through the skin and into the liver. A dye is injected through the needle, so the bile ducts show up on x-rays. By looking at the x-rays, the doctor can tell whether there is a blockage of the bile ducts.

Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. The sample removed from the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease).

One biopsy technique to obtain pancreas tissue is fine needle aspiration, in which a needle is inserted into the pancreas to aspirate (suction out) cells. An x-ray or CT-guided ultrasound is used to help guide the needle. Other ways to collect a sample of pancreas tissue involve the use of ERCP, EUS, or surgery. If the cancer has spread to other organs, a biopsy may be obtained from one of these other sites (such as the liver). A surgical biopsy can be performed either by opening the abdomen or by using a laparoscopic approach to provide openings for a camera and surgical instruments, which requires much smaller incisions.

Some patients, when having surgery or certain types of biopsies, elect to have some of their leftover tissue specimen frozen and sent to independent laboratories to have genetic and molecular profiles performed. This process may help predict which treatments may work best. The use of biospecimens in this manner has not been fully confirmed scientifically in research studies. However, with the increase in new drugs called targeted therapies (see Current Research), it is an area of increasing interest and scientific focus. It is important to note that many insurance companies do not reimburse for these types of tests yet. Talk with your doctor for more information.

Learn more about what to expect when having common tests, procedures, and scans.

Find out more about common terms used during a diagnosis of cancer.