Diagnosing a tumor in the pancreas can be difficult. Symptoms are not always obvious, and usually develop gradually. Several medical tests are often required to establish the diagnosis and to determine whether it has spread beyond the pancreas.
Diagnostic tests for pancreatic cancer include:
Computerized tomography (CT): The CT scan is the primary test used to establish the stage of pancreatic cancer, which determines whether a tumor can be surgically removed. Using a special X-ray machine, this test gives detailed, three-dimensional pictures of the body and can help to determine if the tumor has spread.
Ultrasound is performed by placing a wand on the surface of the abdomen. The wand produces sound waves which form a picture of the inside of the body that is displayed on a computer screen. Ultrasound can help determine the size of the pancreas and possibly the presence of a pancreatic tumor. Endoscopic ultrasound (EUS) involves a special endoscope equipped with an ultrasound probe and a small needle at the end. The scope is placed inside the body through the mouth and esophagus and into the first portion of the small intestine. Surgical instruments, called biopsy forceps or brushes, may be inserted through the endoscope to collect a tissue sample for further testing (biopsy).
Endoscopic retrograde cholangiopancreatography (ERCP) is a procedure used to X-ray the ducts that carry bile from the liver to the gallbladder and from the gallbladder to the small intestine. An endoscope is inserted through the mouth, esophagus and stomach into the first part of the small intestine. A catheter (a smaller tube) is then inserted through the endoscope into the pancreatic ducts. A dye is injected through the catheter and an X-ray is taken. If the ducts are blocked by a tumor, a fine tube, or stent, may be inserted into the duct to unblock it. The stent may be left in place to keep the duct open.
Blood Tests: Currently, no single blood test can make the diagnosis of pancreatic cancer. Some blood tests, known as tumor markers, measure the levels of proteins produced by cancer cells. Known tumor markers for pancreatic cancer include carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA).
Although these tests may be useful when pancreatic cancer is suspected and to monitor the cancer, they are not an effective screening tool. Blood tests can also evaluate the function of the liver and other organs that may be affected by a pancreatic tumor.
Magnetic Resonance Imaging (MRI) uses a magnetic field and pulses of radio wave energy to make pictures of the inside of the body. The area of the body being studied is placed inside a special machine with a strong magnet. In some cases, a contrast material, or dye, may be used during the MRI to show pictures of organs or structures more clearly.
Positron Emission Tomography (PET) uses a special type of scanner and a form of sugar that contains a radioactive atom. This sugar is injected into a vein, and the scanner rotates around the patient's body and records the sugar as it moves through the body and collects in organs. Cancer cells show up brighter in the pictures because they absorb more sugar than normal cells.
Biopsy is the removal of a tissue sample so that it can be viewed under a microscope by a specially trained doctor to check for signs of cancer. There are several ways to do a biopsy for pancreatic cancer.
CT-guided Fine Needle Aspiration (FNA): The CT scan helps the doctor locate the tumor and guide a small needle through the skin and abdomen and into the pancreas to obtain a tissue sample.
Endoscopic Ultrasound FNA: A special endoscope equipped with an ultrasound probe and a small needle at the end is placed through the mouth into the esophagus and the first portion of the small intestine. The physician then performs an ultrasound and uses the needle to obtain a sample of any tissue that appears abnormal.
Laparoscopy: This procedure is done in the operating room under general anesthesia. A thin, lighted tube is guided through a very small (half inch) incision in the abdomen that enables the surgeon to directly visualize the pancreas and determine if the tumor has spread. Tissue samples can also be collected through the scope. Laparoscopy is not performed to diagnose pancreatic cancer, but it may be used to look for evidence that the cancer has spread to other organs, such as the intestines, liver, lymph nodes and stomach.
Staging is the process of describing the extent of the disease at the time of diagnosis. It is essential in choosing a treatment method and assessing prognosis (outcome). Cancer staging is based on the tumor's size, location and whether it has spread to other areas of the body.
Stage 0: Cancer is found only in the lining of the pancreas. Stage 0 is also called carcinoma in situ.
Stage I: Cancer has formed and is found in the pancreas only. Stage I is divided into stage IA and stage IB, based on the size of the tumor.
Stage IA: The tumor is two centimeters or smaller
Stage IB: The tumor is larger than two centimeters
Stage II: Cancer may have spread to nearby tissue and organs, and may have spread to lymph nodes near the pancreas. Stage II is divided into stage IIA and stage IIB, based on where the cancer has spread.
Stage IIA: Cancer has spread to nearby tissue and organs but has not spread to nearby lymph nodes
Stage IIB: Cancer has spread to nearby lymph nodes and may have spread to nearby tissue and organs
Stage III: Cancer has spread to the major blood vessels near the pancreas and may have spread to nearby lymph nodes.
Stage IV: Cancer may be of any size and has spread to distant organs, such as the liver, lung and peritoneal cavity. It may have also spread to organs and tissues near the pancreas or to lymph nodes.