Smoking, chronic pancreatitis, male sex, being black, and possibly long-standing diabetes are risk factors for pancreatic cancer.
Abdominal pain, weight loss, jaundice, and vomiting are some typical symptoms.
Computed tomography, endoscopic ultrasonography, or magnetic resonance imaging are diagnostic techniques.
Pancreatic cancer is usually fatal.
Surgery may cure people whose cancer has not spread.
The pancreas is an organ located in the upper part of the abdomen. It produces digestive juices that are secreted into the digestive tract. The pancreas also produces insulin, which helps control blood sugar. About 95% of cancerous (malignant) tumors of the pancreas are adenocarcinomas. Adenocarcinomas usually originate in the glandular cells lining the pancreatic duct. Most adenocarcinomas occur in the head of the pancreas, the part nearest the first segment of the small intestine (duodenum).
Adenocarcinoma of the pancreas has become increasingly common in the United States, occurring in an estimated 55,440 people each year and causing about 43,330 deaths. Adenocarcinoma usually does not develop before age 50. The average age at diagnosis is 55.
Risk factors for pancreatic cancer include
These tumors are nearly twice as common among men. Adenocarcinoma of the pancreas is 2 to 3 times more common among smokers than nonsmokers. People with chronic pancreatitis are at greater risk as well. People who have relatives with the disease may be at increased risk. Long-standing diabetes may be a risk factor. Alcohol and caffeine consumption do not seem to be risk factors.
Cystadenocarcinoma of the pancreas is a rare type of pancreatic cancer that develops from a fluid-filled noncancerous (benign) tumor called a cystadenoma. It often causes upper abdominal pain and may grow large enough for a doctor to feel it through the abdominal wall. The diagnosis is usually made by a special type of computed tomography (CT) scan of the abdomen or magnetic resonance imaging (MRI). Only 20% of people with this cancer have tumors that have metastasized (spread) by the time surgery is performed. Therefore, cystadenocarcinoma has a much better prognosis than adenocarcinoma. If the cancer has not spread and the whole pancreas is removed surgically, the person has a 65% chance of surviving for at least 5 years.
Intraductal papillary-mucinous tumor is a rare type of pancreatic tumor characterized by enlargement (dilation) of the main pancreatic duct, mucus overproduction, recurring episodes of pancreatitis, and occasional pain. The diagnosis is made by CT and sometimes other imaging tests. These tumors can progress to cancer, but because diagnostic tests cannot distinguish between noncancerous and cancerous forms of this tumor, surgery is the best diagnostic and treatment option for all people suspected of having this type of tumor. With surgery, people with the noncancerous tumors have a greater than 95% chance of surviving for 5 years. People with cancerous tumors have a 50 to 75% chance of surviving 5 years.
Adenocarcinoma of the body or tail of the pancreas (the middle part of the pancreas and the part farthest from the duodenum) typically causes no symptoms until the tumor has grown large. Thus, at the time of diagnosis, the tumor has already spread (metastasized) beyond the pancreas in 90% of cases. Eventually, most people develop severe upper abdominal pain, which may also be felt in the middle of the back. The pain may be relieved by bending forward or assuming the fetal position. Weight loss is common.
Tumors in the head of the pancreas can interfere with the drainage of bile (the digestive fluid produced by the liver) into the small intestine (see Gallbladder and Biliary Tract). Therefore, jaundice (a yellowish discoloration of the skin and the whites of the eyes) caused by obstruction of bile flow is typically an early symptom. The jaundice is accompanied by itchiness all over the body resulting from the deposit of bile salt crystals under the skin. Vomiting may result from instances when cancer in the head of the pancreas obstructs the flow of stomach contents into the small intestine (gastric outlet obstruction) or obstructs the small intestine itself.
Adenocarcinoma of the body or tail of the pancreas may obstruct the vein draining the spleen (the organ that produces, monitors, stores, and destroys blood cells), resulting in enlargement of the spleen (splenomegaly). Obstruction can also cause the veins to become swollen and twisted (varicose) around the esophagus (esophageal varices) and stomach. Severe bleeding may result, particularly from the esophagus, if these varicose veins rupture.
Certain cells in the pancreas produce insulin, a hormone that is essential to control blood sugar levels. Lack of insulin causes diabetes. Thus, because pancreatic cancer cells replace normal pancreatic cells, diabetes develops in 25 to 50% of people, which leads to symptoms of high blood sugar, such as frequently urinating large volumes and excessive thirst.
Pancreatic cancer can also interfere with production of digestive enzymes by the pancreas, resulting in problems breaking down food and absorbing nutrients (malabsorption). This malabsorption causes bloating and gas and a watery, greasy, and/or foul-smelling diarrhea, leading to weight loss and vitamin deficiencies.
Early diagnosis of tumors in the body or tail of the pancreas is difficult because symptoms occur late and physical examination and blood test results are often normal. When adenocarcinoma of the pancreas is suspected, the preferred tests are CT or a specialized type of MRI called MRCP (see Magnetic Resonance Imaging).
Other commonly used tests are endoscopic ultrasonography (a tiny ultrasound probe on the tip of an endoscope is passed through the mouth into the stomach and the first segment of the small intestine), endoscopic retrograde cholangiopancreatography (see Figure: Understanding Endoscopic Retrograde Cholangiopancreatography). Blood tests are also done.
To confirm the diagnosis of pancreatic cancer, a doctor may obtain a sample of the pancreas for examination under a microscope (biopsy) by inserting a needle through the skin using a CT or ultrasound scan as a guide. However, this approach sometimes misses the tumor. The same approach may be used to obtain a biopsy sample from the liver to look for cancer that has spread from the pancreas. If the results of these tests are normal but the doctor still strongly suspects adenocarcinoma, the pancreas may be evaluated surgically.
The only hope of a cure is surgery, which is performed on the 10 to 20% of people in whom it is believed that the cancer has not spread. Either the pancreas alone or the pancreas and the duodenum are removed. Chemotherapy and radiation therapy are usually also given. After these treatments, about 40% of people live at least 2 years, and 25% live at least 5 years.
Obstruction of bile flow may be temporarily relieved by placement of a tube (stent) in the lower portion of the duct that drains bile from the liver and gallbladder. An alternative treatment method is the surgical creation of a channel that bypasses the obstruction. For example, an obstruction of the small intestine can be bypassed by a channel that connects the stomach with a portion of the small intestine that is beyond the obstruction. If these procedures do not relieve itchiness, people may be given cholestyramine by mouth.
Mild pain may be relieved by aspirin or acetaminophen. Most often, stronger painkillers, such as codeine, oxycodone, or morphine, are needed. For people with severe pain, injections into nerves to block pain sensations may provide relief.
The lack of pancreatic digestive enzymes can be treated with oral enzyme preparations. If diabetes develops, insulin treatment may be needed.
Because adenocarcinoma of the pancreas is fatal in most cases, a doctor usually discusses end-of-life care with the person, family members, and other health care practitioners (see Treatment Options at the End of Life).