Diagnosing pancreatic cancer can be difficult. Symptoms are not always obvious and develop gradually. However, there is no standard diagnostic test for pancreatic cancer. Most people with pancreatic cancer first present to their primary-care doctor complaining of nonspecific symptoms. These complaints trigger an evaluation often including a physical examination (usually normal), blood tests, X-rays, and an ultrasound.
If pancreatic cancer is present, the likelihood of an ultrasound revealing an abnormality in the pancreas is about 75%. If a problem is identified, frequently a computed tomography (CT) scan is performed as the next step in the evaluation. Your doctor may order Magnetic Resonance Imaging (MRI) or and Endoscopic Ultrasound (EUS) as a means of evaluation. A confirmation of a pancreatic mass and the suspicion of pancreatic cancer is then raised, and a biopsy is performed to yield a diagnosis.
Different strategies can be used to perform a biopsy of the suspected cancer. Often, a needle biopsy of the liver through the stoamch/belly wall (percutaneous liver biopsy) will be used if it appears that there has been spread of the cancer to the liver. If the tumor remains localized to the pancreas, a biopsy directly of the pancreas is performed via Endoscopic Retrograde Cholangiopancreatography (ERCP). Ultimately, a tissue diagnosis is the only way to make the diagnosis with certainty, and the team of doctors work to obtain a tissue diagnosis in the easiest way possible.
In addition to radiologic tests, suspicion of a pancreatic cancer can arise from the elevation of a "tumor marker," a blood test which can be abnormally high in people with pancreatic cancer. The tumor marker most commonly associated with pancreatic cancer is called the CA 19-9. It is often released into the bloodstream by pancreatic cancer cells and may be elevated in patients newly found to have the disease. Unfortunately, the CA 19-9 test is not specific for pancreatic cancer. Despite ongoing research to diagnose pancreatic cancer earlier, no effective blood test has been developed to screen for this cancer.
Pancreatic Cancer Canada recently released a pamphlet entitled "You've just been diagnosed with pancreatic cancer... What's next?" to help patients better understand their treatment options.
Below are some of the diagnostic and tumor measurement tools used to diagnose or rule out pancreatic cancer and monitor people with pancreatic cancer.
CT Scan is one of the most common imaging procedures performed when an individual is suspected of having pancreatic cancer. The images are often used to determine whether the tumor can be surgically removed. A contrast dye may be given orally or injected into a vein (by IV) to show small tumors of the pancreas and whether the cancer has spread.
Magnetic Resonance Imaging (MRI) is where a doctor uses radio waves and powerful magnets, instead of X-rays as in a CT scan, to view internal structures and organs. The energy from the radio waves is absorbed by the body and then released. A computer translates the patterns formed by this energy release into detailed images of areas inside the body.
Endoscopic Ultrasound (EUS) is where the doctor passes a thin, flexible lighted tube through the patient's mouth and stomach, down into the first part of the small intestine. At the tip of the endoscope is an ultrasound device that makes sound waves and images. The doctor slowly withdraws the endoscope from the intestine toward the stomach to make images of the pancreas and surrounding organs and tissues.
Endoscopic Retrograde Cholangiopancreatography (ERCP) is when the doctor passes an endoscope through the patient's mouth and stomach, down into the first part of the small intestine. The doctor then slips a smaller tube (catheter) through the endoscope into the bile ducts and pancreatic ducts. After injecting dye through the catheter into the ducts, the doctor takes x-ray pictures. The x-rays can show whether the ducts are narrowed or blocked by a tumor or other condition. During an ERCP, other biopsy methods can be performed, such as a brush biopsy. During this procedure, a small brush is introduced through the endoscope to rub off cells from the bile duct or pancreatic duct.
Fine-Needle Aspiration (FNA) Biopsy is where a doctor uses a long, thin needle to obtain tissue specimens. The CT or EUS imaging method allows the doctor to view the position of the needle to ensure that the needle is in the tumor. EUS also can be used to place the needle directly through the wall of the duodenum or stomach and into the tumor for collection of tissue specimens. General anaesthesia is not required, but local anesthesia may be provided.