Pancreatic Cancer (cont.)

Cancers that develop within the pancreas fall into two major categories: (1) cancers of the endocrine pancreas (the part that makes insulin) are called "islet cell" or "pancreatic neuroendocrine" cancers and (2) cancers of the exocrine pancreas (the part that makes enzymes). Islet cell cancers are rare and typically grow slowly compared to exocrine pancreatic cancers. Islet cell tumors often release hormones into the bloodstream and are further characterized by the hormones they produce (insulin, glucagon, gastrin, and other hormones). Cancers of the exocrine pancreas develop from the cells that line the system of ducts that deliver enzymes to the small intestine and are called commonly referred to as pancreatic adenocarcinomas. Adenocarcinoma of the pancreas comprises 95% of all pancreatic ductal cancers and is the subject of this review.

Cells that line the ducts in the exocrine pancreas divide more rapidly than the tissues that surround them. For reasons that we do not understand, these cells can make a mistake when they divide and an abnormal cell can be made. When an abnormal ductal cell begins to divide in an unregulated way, a growth can form. These changes are called "dysplasia." Often, dysplastic cells can undergo additional genetic mistakes over time and become even more abnormal. If these dysplastic cells then begin to invade through the walls of the duct from which they arise into the surrounding tissue, a frank cancer develops.

About 40,000 cases of pancreatic cancer occur yearly in the United States. Most people who develop pancreatic cancer do so without any predisposing risk factors. Perhaps the biggest risk factor is increasing age; being over the age of 60 puts an individual at greater risk. Rarely, there can be genetic syndromes that run in families that put individuals at higher risk such as BRCA-2 and, to a lesser extent, BRCA-1 gene mutations. Familial syndromes are unusual but it is important to let your doctor know if anyone else in your family has been diagnosed with cancer. Additionally, certain behaviors or conditions are thought to slightly increase an individual's risk for developing pancreatic cancer. For example, African-Americans may be at greater risk as may individuals with close family members who have been previously diagnosed with the disease. Other behaviors or conditions that may put people at risk include tobacco use, obesity, a sedentary lifestyle, a history of diabetes, chronic pancreatic inflammation (pancreatitis), and a fatty (or Western) diet. Prior stomach surgery may moderately increase one's risk as can certain chronic infections such as hepatitis B and H. pylori (an infection of the stomach lining). Certain types of pancreatic cysts may put individuals at risk of developing pancreatic cancer. Despite these associated risks, no identifiable cause is found in most people who develop pancreatic cancer.

Source: MedicineNet.com
http://www.medicinenet.com/pancreatic_cancer/article.htm