What is pancreatic cancer?
Pancreatic cancer is a disease in which cancerous cells are found within the tissues of the pancreas. The pancreas is a six-inch long, pear-shaped gland that lies behind the stomach, surrounded by other digestive organs, such as the liver, gallbladder, and small intestine. It has two main functions, to produce digestive juices that help break down food, and to
produce hormones (like insulin) that control how the body stores and uses the food.
Pancreatic cancer is an abnormal, uncontrolled growth of cells in the pancreas, which is a digestive gland located behind the stomach. The pancreas is both an exocrine and endocrine gland, meaning that it releases secretions into ducts (exocrine) as well as directly into the bloodstream (endocrine). More than 95 percent of the cells in the pancreas are exocrine; these glands produce pancreatic juice, which contains enzymes that break down fats, proteins and carbohydrates. The small percentage of cells that are endocrine are organized into small clusters called islets of Langerhans. These cells release the hormones insulin and glucagon that are essential to controlling the amount of sugar in the blood.
Cancer of the exocrine pancreas is more common, accounting for the majority of pancreatic cancer cases. Adenocarcinoma, often beginning the in the pancreatic ducts, is the most prevalent type of pancreatic cancer. As the disease progresses, the tumor may invade surrounding organs such as the stomach and small intestine, or metastasize to more distant sites in the body. Tumors of the endocrine pancreas, or islet cell tumors, are much less common, and most are benign. This section discusses exocrine cancers of the pancreas.
The part of the pancreas that produces the digestive juices is called the exocrine pancreas, and almost 95% of pancreatic cancers occur in the tissues of the exocrine pancreas. The hormone-producing area of the pancreas is the endocrine pancreas and only 5% of the tumors originate there. Though pancreatic cancer accounts for only 2-3% of all cancers, it is the fourth most frequent cause of cancer deaths. It is estimated that at least 29,000 new cases of pancreatic cancer will be diagnosed in the United States in 1998. Unfortunately, cancer of the pancreas is often fatal, and only 18% will survive one year after diagnosis. The five-year survival rate is 4%. This is because by the time a patient exhibits symptoms, and the cancer is diagnosed, it is no longer in its early stages. It has usually spread to other organs such as the lung and the liver.
The incidence of pancreatic cancer increases with age, and most cases are detected in individuals aged 60 or older. Men are also 30% more likely to develop cancer of the pancreas than are women. African Americans have been noted to have a higher frequency of pancreatic cancer than European Americans and Asian Americans. However, whether the increase is because of race or the influence of diet cannot be really ascertained. Studies have shown that among Africans and Asians whose diet is lower in fat than African Americans and Asian Americans, the incidence of pancreatic cancer is significantly lower.