How Is Pancreatic Cancer Diagnosed?
On physical exam, the doctor may feel a mass in the center of the abdomen. However, pancreatic cancer is seldom diagnosed using a physical exam, and the absence of any abnormalities should not dissuade the doctor from obtaining an imaging test if the symptoms of pancreatic cancer are present and persistent. The main imaging tests used to help detect pancreatic cancer are as follows:
- Abdominal ultrasound: This may be the initial test if a person has abdominal pain and jaundice. This test is effective at looking for gallstones, a common condition that presents with similar symptoms as that of pancreatic cancer. If a pancreatic tumor is seen on ultrasound, a CT scan is still necessary to obtain more information.
- Abdominal computed tomography (CT): This is the test of choice to help diagnose pancreatic cancer. A CT scan can locate small tumors in the pancreas that might be missed by ultrasound. In addition, a CT scan can accurately show whether the mass has extended beyond the pancreas and what the relation is to nearby blood vessels and organs -- information vital to a surgeon planning an operation to remove the cancer. If a pancreatic tumor is suspected, then a specialized CT scan, called a pancreatic protocol scan, is preferred prior to surgery.
- Other tests include MRI, positron emission tomography (PET scan), and endoscopic techniques.
If a tumor is seen in the pancreas, the doctor may want to perform a biopsy so that a pathologist can confirm that the mass is cancer. A biopsy can be performed in the following ways:
- Percutaneous biopsy: This refers to a biopsy performed by inserting a needle through the skin into the body. A radiologist usually performs this procedure while using an ultrasound or CT scanner to guide the needle into the tumor. The procedure is generally painless.
- Endoscopic biopsy: A gastroenterologist performs this procedure by inserting a flexible tube with a camera at the tip (called an endoscope) through the mouth, into the stomach, and then into the duodenum. From here, a needle biopsy can be obtained with guidance from an ultrasound at the tip of the endoscope. A person is heavily sedated for this procedure, and it is generally painless.
If a tumor is seen in the pancreas and little doubt exists that the tumor is cancer, a surgeon may choose to attempt to remove the cancer completely without first obtaining a biopsy.
Once the diagnosis of pancreatic cancer is confirmed, routine blood studies are also performed to assess overall liver and kidney function.
In addition, a blood test called CA 19-9 is obtained. CA 19-9 is often produced by pancreatic cancers, and its level is elevated in about 80% of pancreatic cancer cases. The CA19-9 can not be used to establish a diagnosis of pancreatic cancer by itself. Checking the CA 19-9 levels can be a useful gauge of how the treatment is working.
After treatment, the doctor may check the CA 19-9 levels regularly in patients in whom the test was originally elevated, then fell, as one indicator of whether the cancer has returned after surgery or progressed on prior treatment. However, CA 19-9 is not an absolute test for pancreatic cancers, and other conditions may cause a rise in the CA 19-9 levels. Likewise, a normal or unchanged CA 19-9 level is not a guarantee that the cancer has not returned or progressed.
New research findings released in 2016 may change aspects of pancreatic cancer. Researchers reported genomic analysis of 456 pancreatic ductal adenocarcinomas. Subsequent genetic expression analysis of these adenocarcinomas allowed them to be defined into four subtypes. These subtypes have not been previously discerned. The following is a list of these four new subtypes:
- Squamous: These types of tumors have enriched TP53 and KDMA mutations.
- Pancreatic progenitor: These types of tumors express genes involved in pancreatic development such as FOXA2/3, PDX1, and MNX1.
- Aberrantly differentiated endocrine exocrine (ADEX): These tumors show upregulation of genes (KRAS) and exocrine (NR5A2 and RBPJL) and endocrine (NEUROD1 and NKX2-2) differentiation.
- Immunogenic: These tumors contain pathways that are involved in acquired immune suppression.
These findings may allow future pancreatic cancer patients to be treated more specifically and, hopefully, more effectively. For example, the people with the immunogenic subtype could possibly respond to therapy where the immune system is re-engineered to attack this particular type of pancreatic cancer cell.
Pancreatic Cancer Treatment
The optimal treatment of pancreatic adenocarcinoma depends on the extent of the disease. The extent of cancer can be divided into the following three categories:
- Localized: The cancer is completely confined within the pancreas.
- Locally advanced: The cancer has extended from the pancreas to involve nearby blood vessels or organs by direct extension.
- Metastatic: The cancer has spread outside the pancreas to other parts of the body.