Pancreatic Cancer

Pancreatic cancer is a disease in which malignant (cancer) cells form in the tissues of the pancreas. The pancreas is a gland about 6 inches long that is shaped like a thin pear lying on its side. The wider end of the pancreas is called the head, the middle section is called the body, and the narrow end is called the tail. The pancreas lies behind the stomach and in front of the spine.

The pancreas has two main jobs in the body:

To produce juices that help digest (break down) food.
To produce hormones, such as insulin and glucagon, that help control blood sugar levels. Both of these hormones help the body use and store the energy it gets from food.

The digestive juices are produced by exocrine pancreas cells and the hormones are produced by endocrine pancreas cells. About 95% of pancreatic cancers begin in exocrine cells.

Symptoms and Diagnosis

These and other symptoms may be caused by pancreatic cancer. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:

Jaundice (yellowing of the skin and whites of the eyes).
Pain in the upper or middle abdomen and back.
Unexplained weight loss.
Loss of appetite.
Fatigue.

Pancreatic cancer is difficult to detect and diagnose for the following reasons:

There aren't any noticeable signs or symptoms in the early stages of pancreatic cancer.
The signs of pancreatic cancer, when present, are like the signs of many other illnesses.
The pancreas is hidden behind other organs such as the stomach, small intestine, liver, gallbladder, spleen, and bile ducts.

To diagnose pancreatic cancer, the following tests and procedures may be used:

Chest x-ray: An x-ray of the organs and bones inside the chest.
Physical exam and history: An exam of the body to check general signs of health.
CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography. A spiral or helical CT scan makes a series of very detailed pictures of areas inside the body using an x-ray machine that scans the body in a spiral path.
MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).
PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radionuclide glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells.
Endoscopic ultrasound (EUS): A procedure in which an endoscope (a thin, lighted tube) is inserted into the body. The endoscope is used to bounce high-energy sound waves (ultrasound) off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. This procedure is also called endosonography.
Laparoscopy: A surgical procedure to look at the organs inside the abdomen to check for signs of disease. Small incisions (cuts) are made in the wall of the abdomen and a laparoscope (a thin, lighted tube) is inserted into one of the incisions. Other instruments may be inserted through the same or other incisions to perform procedures such as removing organs or taking tissue samples for biopsy.
Endoscopic retrograde cholangiopancreatography (ERCP): A procedure used to x-ray the ducts (tubes) that carry bile from the liver to the gallbladder and from the gallbladder to the small intestine. Sometimes pancreatic cancer causes these ducts to narrow and block or slow the flow of bile, causing jaundice. An endoscope (a thin, lighted tube) is passed 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 into the ducts and an x-ray is taken. If the ducts are blocked by a tumor, a fine tube may be inserted into the duct to unblock it. This tube (or stent) may be left in place to keep the duct open. Tissue samples may also be taken.
Percutaneous transhepatic cholangiography (PTC): A procedure used to x-ray the liver and bile ducts. A thin needle is inserted through the skin below the ribs and into the liver. Dye is injected into the liver or bile ducts and an x-ray is taken. If a blockage is found, a thin, flexible tube called a stent is sometimes left in the liver to drain bile into the small intestine or a collection bag outside the body. This test is done only if ERCP cannot be done.
Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. There are several ways to do a biopsy for pancreatic cancer. A fine needle may be inserted into the pancreas during an x-ray or ultrasound to remove cells. Tissue may also be removed during a laparoscopy (a surgical incision made in the wall of the abdomen).

Causes

All cancers are caused by dysfunctions of proteins involved in cell division, apoptosis, or DNA repair (see general characteristics). Dysfunctional proteins may arise from gene mutations or protein interactions with environments. The following factors may increase the risk of developing pancreatic cancer:

Smoking.
Long-standing diabetes.
Chronic pancreatitis.
Certain hereditary conditions, such as hereditary pancreatitis, multiple endocrine neoplasia type 1 syndrome, hereditary nonpolyposis colon cancer (HNPCC; Lynch syndrome), von Hippel-Lindau syndrome, ataxia-telangiectasia, and the familial atypical multiple mole melanoma syndrome (FAMMM).

Reference:

National Cancer Institute, USA.