Metastatic Pancreatic Cancer
Metastatic pancreatic cancer refers to cancer of the pancreas that has reached a stage where cancer cells break from the primary tumor and travel through the body in a process called metastasis. The cells move through the lymph system, which transports fluids and performs other functions, and the blood vessels. When the cells settle in a place with sufficient nutrients and are allowed to grow, they form their own tumors. In pancreatic cancer, metastasis usually occurs in organs surrounding the pancreas, though it can travel farther abroad.
Metastatic pancreatic cancer is the most common type of pancreas cancer. Malignant tumors of the pancreas are usually adenocarcinomas, or cancer tumors of the glands. In fact, 90 to 95 of pancreatic cancers are adenocarcinomas. They can develop in the head, tail, and body of the pancreas. But most tumors occur in the cells of the ducts or in the acinar cells, which is a cell type that produces digestive enzymes. Tumors can also occur in the ampulla of Vater, where bile and pancreatic ducts meet the small intestine.
However, endocrine tumors, which appear in the islet cells, are very rare and the types that do appear usually do not form metastatic cancer. The islet cells produce hormones like insulin and glucagon. Tumors growing in them often secrete hormones as well. These are called functional tumors and are named according to what hormone they produce. Tumors that make glucagon are called glucagonomas, insulin producers are insulinomas, and adrenocorticotropic hormone tumors are ACTHomas.
Adenocarcinomas usually first metastasize to the liver or intestinal lining. They may also appear on other nearby structures and surfaces. Around 10 percent of cancer sufferers may have metastatic pancreatic cancer even when CT scans seem to show an adenocarcinoma that can be removed. Only in surgery is the cancer's metastasis discovered. To avoid this, doctors use diagnostic laparoscopy to verify the cancer has not spread. With this technique doctors can view the body's internal structures. When the cancer reaches the liver and its lymph nodes, surgery is usually no longer an option. Even if tests show only a few areas of cancer growth, doctors must assume there are more, smaller groups in other organs as well. Unfortunately, because of their dispersal, radiation therapy is also no longer a viable course of treatment. The only therapy left is chemotherapy. A liquid drug called 5-fluorouracil (5-FU) was once the weapon of choice, but gemcitabine, usually called Gemzar, has largely replaced it. It is more effective than 5-FU, and when other chemo drugs are used with Gemzar the results usually improved. These other drugs are normally oxaliplatin (Eloxatin), capecitabine (Xeloda), and erlotinib (Tarceva). There are others, but theses are the most common and thoroughly tested. But, despite the chemotherapy advances, metastatic pancreatic cancer does not respond well to the treatment. Thus the drugs can really only increase a patient's survival time, not cure the cancer. However, they can increase survival by 2 to 5 months. They also decrease cancer symptoms in some people. Metastatic pancreatic cancer is a fearsome disease, killing almost 30,000 people yearly. It is important to catch cancer early. A tumor that has not yet metastasized has a much better prognosis than one that has colonized other organs.
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