Diagnosis

If a patient has symptoms that suggest pancreatic cancer, the doctor asks about the patient's medical history. The doctor may perform a number of procedures, including one or more of the following:

• Physical exam -- The doctor examines the skin and eyes for signs of jaundice. The doctor then feels the abdomen to check for changes in the area near the pancreas, liver, and gallbladder. The doctor also checks for ascites, an abnormal buildup of fluid in the abdomen.

• Lab tests -- The doctor may take blood, urine, and stool samples to check for bilirubin and other substances. Bilirubin is a substance that passes from the liver to the gallbladder to the intestine. If the common bile duct is blocked by a tumor, the bilirubin cannot pass through normally. Blockage may cause the level of bilirubin in the blood, stool, or urine to become very high. High bilirubin levels can result from cancer or from noncancerous conditions.

• CT scan (Computed tomography) -- An x-ray machine linked to a computer takes a series of detailed pictures. The x-ray machine is shaped like a donut with a large hole. The patient lies on a bed that passes through the hole. As the bed moves slowly through the hole, the machine takes many x-rays. The computer puts the x-rays together to create pictures of the pancreas and other organs and blood vessels in the abdomen.

• Ultrasonography -- The ultrasound device uses sound waves that cannot be heard by humans. The sound waves produce a pattern of echoes as they bounce off internal organs. The echoes create a picture of the pancreas and other organs inside the abdomen. The echoes from tumors are different from echoes made by healthy tissues.

  The ultrasound procedure may use an external or internal device, or both types:

  • Transabdominal ultrasound: To make images of the pancreas, the doctor places the ultrasound device on the abdomen and slowly moves it around.

  • EUS (Endoscopic ultrasound): The doctor passes a thin, lighted tube (endoscope) 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. The doctor slowly withdraws the endoscope from the intestine toward the stomach to make images of the pancreas and surrounding organs and tissues.

• ERCP (endoscopic retrograde cholangiopancreatography) -- The doctor passes an endoscope through the patient's mouth and stomach, down into the first part of the small intestine. The doctor 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.

• PTC (percutaneous transhepatic cholangiography) -- A dye is injected through a thin needle inserted through the skin into the liver. Unless there is a blockage, the dye should move freely through the bile ducts. The dye makes the bile ducts show up on x-ray pictures. From the pictures, the doctor can tell whether there is a blockage from a tumor or other condition.

• Biopsy -- In some cases, the doctor may remove tissue. A pathologist then uses a microscope to look for cancer cells in the tissue. The doctor may obtain tissue in several ways. One way is by inserting a needle into the pancreas to remove cells. This is called fine-needle aspiration. The doctor uses x-ray or ultrasound to guide the needle. Sometimes the doctor obtains a sample of tissue during EUS or ERCP. Another way is to open the abdomen during an operation.

When pancreatic cancer is diagnosed, the doctor needs to know the stage, or extent, of the disease to plan the best treatment. Staging is a careful attempt to find out the size of the tumor in the pancreas, whether the cancer has spread, and if so, to what parts of the body.

The doctor may determine the stage of pancreatic cancer at the time of diagnosis, or the patient may need to have more tests. Such tests may include blood tests, a CT scan, ultrasonography, laparoscopy, or angiography. The test results will help the doctor decide which treatment is appropriate.

Causes 

Your pancreas is about 6 inches long and looks something like a pear lying on its side. The wider end (head) is located near the center of your abdomen next to the upper part of your small intestine (duodenum). The main part (body) of the pancreas stretches behind your stomach, and the narrow end (tail) is on your left side, next to your spleen. 

A part of your digestive system, your pancreas performs two essential functions: 

• It produces digestive juices and enzymes  that help break down proteins, carbohydrates and fats so the food you eat can be digested in your small intestine. 
• It secretes the hormones insulin and glucagon  that regulate the way your body metabolizes sugar (glucose). 

Most of your pancreas is composed of cells that produce digestive enzymes and juices. Pancreatic juices flow into the main pancreatic duct, which leads to your small intestine (duodenum). The pancreatic duct joins up with the tube leading from your gallbladder to form the common bile duct, which then empties into the small intestine. Your pancreas also contains small "islands" of cells that secrete the hormones insulin and glucagon, along with somatostatin. 

Types of pancreatic cancer 
Most pancreatic tumors originate in the duct cells or in the cells that produce digestive enzymes (acinar cells). Called adenocarcinomas, these tumors account for nearly 95 percent of pancreatic cancers. 

Tumors that begin in the islet cells (endocrine tumors) are much less common. When they do occur, they may cause the affected cells to produce too much hormone. For example, tumors in glucagon cells (glucagonomas) might cause excess amounts of glucagon to be secreted, while tumors in insulin cells (insulinomas) may lead to an overproduction of insulin. 

Tumors can also develop in the ampulla of Vater - the place where your bile and pancreatic ducts empty into your small intestine. Called ampullary cancers, these tumors often block the bile duct, leading to jaundice. Because even a small tumor can obstruct the bile duct, signs and symptoms of ampullary cancer usually appear earlier than do symptoms of other pancreatic cancers. 

Why pancreatic cancer occurs 
Healthy cells grow and divide in an orderly way. This process is controlled by DNA - the genetic material that contains the instructions for every chemical process in your body. When DNA is damaged, changes occur in these instructions. One result is that cells may begin to grow out of control and eventually form a tumor - a mass of malignant cells. 

Researchers don't know exactly what damages DNA in the vast majority of cases of pancreatic cancer. But it is known that a small percentage of people develop the disease as a result of a genetic predisposition. These people who have a close relative, such as a parent or sibling, with pancreatic cancer have a higher risk of developing pancreatic cancer themselves. 

In addition, a number of genetic diseases have been associated with an increased risk of pancreatic cancer, including familial adenomatous polyposis, nonpolyposis colon cancer, familial breast cancer associated with the BRCA2 gene, hereditary pancreatitis, and familial atypical multiple mole-melanoma syndrome - a serious type of skin cancer. This means that people who have a hereditary predisposition to develop these cancers are also more likely to develop pancreatic cancer. 

Yet only about 10 percent of pancreatic cancers result from an inherited tendency. A greater number are caused by environmental or lifestyle factors, such as smoking, diet and chemical exposure.