Today, I link to and excerpt from Cancer.Net‘s Pancreatic Cancer: Diagnosis. Approved by the Cancer.Net Editorial Board, 09/2023.
All that follows is from the above resource.
Pancreatic Cancer Guide
How pancreatic cancer is diagnosed
If a doctor suspects that a person has pancreatic cancer, they will first ask about the person’s medical history and family history. Then, they will examine the person to look for signs of the disease. An appropriate and timely diagnosis is very important. If possible, tests should be done at a medical center that has experience with the disease. The tests described below may be used when pancreatic cancer is suspected. However, the diagnosis should be confirmed with a sample of tissue from the tumor taken during a biopsy or surgery.
Imaging tests
Imaging tests show pictures of the inside of the body. They can help doctors find out where the cancer is located and whether it has spread from the pancreas to other parts of the body. Imaging tests may also be used to monitor whether the cancer is growing. Pancreatic cancer often does not develop as a single large tumor, which means it can sometimes be difficult to see on imaging tests. However, newer computed tomography scanners (see below) produce better, clearer images that can make it easier to find a tumor. A radiologist is a doctor who specializes in interpreting imaging tests.
- Computed tomography (CT or CAT) scan. A CT scan takes pictures of the inside of the body using high-speed x-rays taken from different angles. A computer combines these pictures into a detailed, multi-dimensional image (typically 3-dimensional or more) that shows any abnormalities or tumors. A CT scan can be used to determine the size and location of the primary tumor and evaluate the possibility of spread to lymph nodes or other parts of the body. Typically, a special dye called a contrast medium is given before the scan to provide better detail on the image. This dye can be injected into a patient’s vein or given as a pill or liquid to swallow.Many cancer centers use a special CT scan method called a pancreatic protocol CT scan*. This method ffocuses on taking pictures of the pancreas at specific times after the intravenous (IV) injection of contrast medium to find out exactly where the tumor is in relation to nearby organs and blood vessels. The results of this test can help decide if the tumor could be removed with surgery.
*CT pancreas (protocol)
Last revised by Raymond Chieng on 15 Apr 2023 from Radiopaedia.
- The American Society of Clinical Oncology (ASCO) recommends that people with metastatic pancreatic cancer should get a CT scan done of their chest, abdomen, and pelvis to evaluate the extent of the cancer. A CT scan or other imaging may also be used 2 to 3 months after standard treatment begins to evaluate treatment effectiveness.
- Positron emission tomography (PET) scan or PET-CT scan. A PET scan creates multi-colored pictures of organs and tissues inside the body. A PET scan is usually combined with a CT scan (see above), called a PET-CT scan. Sometimes, it may be combined with magnetic resonance imaging (MRI; see below). However, you may hear your doctor refer to this procedure just as a PET scan. A small amount of a radioactive sugar substance called a tracer is injected into the patient’s body. The most common tracer used in pancreatic cancer PET scans is fluorodeoxyglucose (FDG). This sugar substance is taken up by cells that use the most energy and will cause them to “light up” much brighter on the PET scan. Because cancer tends to use energy actively, it absorbs more of the radioactive tracer substance. However, the amount of radiation in the substance is intentionally designed to be too low to be harmful. There are also non-cancerous reasons an area can light up, such as an infection or active organ functioning. A PET scanner detects the injected substance to produce images of the inside of the body. The combination provides a more complete picture of the area being evaluated. A PET scan alone should never be used instead of a high-quality, high-speed CT scan. PET scans differ from CT scans in that CT scans are looking at the tumor in relation to your anatomy, while PET scans are attempting to measure metabolic activity. The 2 tests are typically used together for pancreatic cancer.
- Endoscopic retrograde cholangiopancreatography (ERCP). This procedure is performed by a gastroenterologist. A gastroenterologist is a doctor who specializes in the gastrointestinal tract, including the stomach, intestines, and similar organs. The doctor will put a thin, lighted tube called an endoscope through the mouth and stomach into the small intestine. Then, a smaller tube called a catheter is passed through the endoscope and into the bile ducts and pancreatic ducts. Dye is injected into the ducts, and the doctor 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. Samples of the tissue can be taken during this procedure and can sometimes help confirm the diagnosis of cancer. The patient is lightly sedated during this procedure. ERCP is generally used to place bile duct stents and not commonly used for diagnosis.
- Ultrasound. An ultrasound creates a picture of the internal organs using sound waves. There are 2 types of ultrasound devices:
- A transabdominal ultrasound device is placed against the outside of the abdomen and is slowly moved around by the doctor to produce an image of the pancreas and surrounding structures.
- An endoscopic ultrasound (EUS) device is a thin, lighted tube that is passed through the patient’s mouth and stomach and down into the small intestine. It is slowly moved around the area to take a picture of the pancreas. This procedure is very specialized and requires a gastroenterologist who has special training in this area. EUS is generally done under sedation, so the patient sleeps through the procedure. A biopsy (see below) may also be done at the same time as 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.
- Magnetic resonance imaging (MRI). An MRI produces detailed images of the inside of the body using magnetic fields, not x-rays. MRI can be used to measure the tumor’s size. A special dye called a contrast medium is given before the scan to create a clearer picture. This dye can be injected into a patient’s vein or given as a pill or liquid to swallow. Magnetic resonance cholangiopancreatography (MRCP) is a specialized type of MRI using computer software developed specifically to examine pancreatic issues, such as ductal blockages and cysts.
Biopsy and tissue tests
- Biopsy. A biopsy is the only way to make a definite diagnosis, even if other tests can suggest that cancer is present. During biopsy, a small amount of tissue is removed for examination under a microscope. A pathologist analyzes the sample(s). A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease. For pancreatic cancer, the pathologist may often have specific experience in looking at pancreatic cancer biopsy samples.
- If the cancer has spread to other organs, a biopsy may also be needed from 1 of these other areas, such as the liver. Again, this can be through the skin, as explained above, or by surgery, which is less common. This type of surgery can be done through a larger incision in the abdomen, called a laparotomy. Or, it can be done using much smaller incisions that provide openings for a tiny camera and surgical instruments, called a laparoscopic approach.
- Occasionally, a biopsy may show that there are no cancer cells in the area tested even if there are. This result is called a “false negative” and may also be described as being “inconclusive.”
- Biomarker, or molecular, testing of the tumor. Your doctor may recommend, and you may request, additional molecular tests to be performed on the tumor sample to identify specific mutations, genetic alterations, expression of certain proteins, and other molecular features unique to the tumor. Some of these tests can be done in your local hospital laboratory. For other tests, the sample may need to be sent to an independent laboratory for analysis.Examples of molecular testing that should be performed include looking for evidence of high microsatellite instability (MSI-high) or defective mismatch repair (dMMR); for mutations in the BRCA gene, as well as other genes involved in DNA damage repair; and for a specific genetic alteration called an NTRK fusion. These tests may help doctors determine your treatment options, including immunotherapy and targeted therapy. However, these findings are not common in pancreatic tumors. The most common genes that are mutated in pancreatic cancer include KRAS, p16/CDKN2A, TP53, and SMAD4/DPC4. There are currently no approved drugs that target these specific mutations, aside from 1 drug that targets a rare type of KRAS mutation. However, more research is being done in this area.Molecular testing can be commonly referred to as “testing for targeted therapies,” “personalized medicine,” “precision medicine,” or “next generation sequencing.” This field of science and treatment is rapidly growing and is an area of increasing interest, scientific focus, and research progress. It is helpful to find out the type and amount of tumor sample needed for these tests and if they are covered by your health insurance. You may need to have another biopsy to get a large enough tissue sample for more extensive testing. Depending on the type of testing, a blood test sometimes referred to as a “liquid biopsy” can provide information on some of the molecular or genetic features of your cancer by analyzing the DNA shed by tumor cells into the bloodstream, known as circulating tumor DNA (ctDNA). Know that these results sometimes take weeks to return, and you do not necessarily wait for the results before starting treatment.For tests such as drug assays, talk with your doctor about the potential information they could provide that would help plan your treatment and whether such tests are covered by your insurance. It is important to discuss these options in advance with the health care professional who will be performing the procedure for the diagnosis. This is to ensure the health care team and technicians have the proper instructions for the procedure should tumor testing be involved.
People who have surgery may also choose to donate parts of the tumor that are not needed for their diagnosis or cancer care so the samples can be used to further pancreatic cancer research. (Learn more about biospecimens in cancer research in a separate article on this website.)
- Germline testing. It is now recommended that all people with a diagnosis of pancreatic cancer be considered for germline testing (see Risk Factors). This means testing a blood or saliva sample to look for mutations in a person’s DNA that may indicate a hereditary predisposition to cancer. This is typically performed in addition to a visit with a genetic counselor. If a person is found to be a carrier for particular genetic mutations, this may help guide the treatment decisions if pancreatic cancer is diagnosed. It would also signal that their family members may want to consider genetic testing and participation in a pancreatic cancer family registry.
After diagnostic tests have been performed, your doctor will review the results with you, including the exact type of cancer you have, how much the cancer has grown and spread (called the stage), and the options for treatment. You may request copies of all test results and images for your own personal medical records.
The next section in this guide is Stages. It explains the system doctors use to describe the extent of the disease. Use the menu to choose a different section to read in this guide [Pancreatic Cancer Guide] at the very top of this page.
