Type Pancreatic Cancer

Type Pancreatic Cancer

Pancreas
Epidemiologists estimate that smoking causes 30 percent of all cases of pancreatic cancer, the fourth leading cause of cancer death in the United States. The pancreas has both a digestive and a hormonal function. Composed mainly of exocrine tissue, it secretes enzymes into the small intestine, where they help break down fats, carbohydrates, and proteins. Pockets of endocrine cells called the islets of Langerhans produce glucagon and insulin, hormones that regulate blood-sugar levels. About 95 percent of all pancreatic cancers begin in the exocrine tissue.

Each year about 28,300 Americans and 3,100 Canadians are diagnosed with cancer of the pancreas, a small gland sandwiched between the stomach and intestine that secretes chemicals used in digestion. Epidemiologists estimate that smoking causes about 30 percent of all cases of pancreatic cancer. Men are 30 percent more likely to develop this type of cancer than women, and in the United States, pancreatic cancer affects African Americans more than any other ethnic group.

The pancreas is composed of two different types of glands: exocrine and endocrine glands. Exocrine glands, which make up the bulk of the pancreas, produce enzymes that help the body break down fats and proteins. About 5 percent of the cells in the pancreas are endocrine glands. These cells secrete the hormones insulin and glucagon, which help control blood sugar levels. About 95 percent of all cancers that originate in the pancreas are adenocarcinomas of the exocrine glands. Cancers of the endocrine glands are very rare, and the following discussion pertains to cancer of the exocrine glands.

Although rarer than many types of cancer, pancreatic cancer is the fourth leading cause of cancer death in the United States because it produces few if any symptoms before it metastasizes. When symptoms are present, they may include jaundice, a yellowing of the skin, eyes, and fingernails; abdominal pain; weight loss; and digestive problems. Usually by the time symptoms appear, the cancer has spread to distant organs in the body. For this reason, only about 4 percent of all people diagnosed with pancreatic cancer in the United States survive five years or more.

Contributed By:Karen R. Peterson

Leukemia

Leukemia

Hairy Cell Leukemia
Pathologists can distinguish various types of leukemia by the appearance of the cancerous cells underneath a microscope. Hairy cell leukemia, a rare form of chronic lymphocytic leukemia, is characterized by cells with minute, hairlike projections on their surface.

Leukemia is cancer of the blood cells. About 31,000 new cases of leukemia are diagnosed in the United States and 3,500 new cases are diagnosed in Canada each year. Leukemia is typically thought to be a childhood disease, but in fact it strikes many more adults. Smoking increases the risk of developing leukemia, as does long-term exposure to high levels of the chemical benzene and high-dose radiation exposure.
There are four types of leukemia, classified by the type of blood cell affected and whether the cells are mature or immature. The four major types are acute myelocytic leukemia (AML), chronic myelocytic leukemia (CML), acute lymphocytic leukemia (ALL), and chronic lymphocytic leukemia (CLL). AML and CLL are most common in adults, while ALL is the most common form in children. CML also affects adults. Acute leukemias progress rapidly, while chronic leukemias tend to develop slowly.

Most symptoms of leukemia result from the lack of normal blood cells that occurs when leukemia cells crowd out normal cells. General symptoms include weight loss, fever, and loss of appetite, and less often, profuse bleeding from the gums and mucous membranes under the skin. Low levels of red blood cells may also indicate the presence of leukemia.
In the United States the five-year survival rate varies according to the type of leukemia and the age of the patient. Almost 68 percent of the people diagnosed with CLL live at least five years. The five-year survival rate for adult ALL is almost 56 percent and is 70 percent for children with ALL. More than 27 percent of those diagnosed with CML survive five years or more. AML is the most fatal of the leukemias. The five-year survival rate for adults with this disease is just over 11 percent, while for children it is 40 percent.

Contributed By:Karen R. Peterson