Encyclopedia of Health and Medicine

80 The Gastrointestinal System
acts to slow the release of other digestive enzymes
as well. The pancreas releases glucagon when
blood glucose levels fall. Glucagon signals the liver
to convert glycogen to glucose.
COMMON CONDITIONS THAT CAN
AFFECT THE PANCREAS
DIABETES
gallstones in the common bile duct
PANCREATIC CANCER pancreatic cyst
pancreatic pseudocyst PANCREATITIS
For further discussion of the pancreas and the
functions of the islets of Langerhans within the
context of gastrointestinal structure and function,
please see the overview section “The Gastrointestinal
System.”
See also DIABETES; DIET AND HEALTH.
pancreatic cancer Malignant growths of the
PANCREAS. Pancreatic CANCER seldom shows symptoms
until the cancer is well advanced or metastasized,
making it among the most lethal cancers
and the fourth leading cause of deaths from cancer
in the United States. The one-year survival
rate is about 24 percent.
When symptoms do appear as the cancer
advances, they include
• JAUNDICE, a yellowish discoloration of the SKIN
that results from the cancer compressing the
common bile duct and blocking the flow of BILE
into the DUODENUM
• ABDOMINAL PAIN that may radiate to the back
• digestive disturbances that result from the cancer’s
interference with pancreatic enzyme production
or blockage of the ducts that carry the
secretions out of the pancreas
The diagnostic path includes imaging procedures
such as ULTRASOUND, COMPUTED TOMOGRAPHY
(CT) SCAN, or POSITRON EMISSION TOMOGRAPHY (PET)
SCAN to determine the location and extent of the
cancer as well as LYMPH NODE involvement and
regional METASTASIS. Percutaneous (needle) biopsy
confirms the diagnosis.
Treatment depends on how extensively the
cancer has spread. Surgery is most effective when
the cancer is small, remains confined to the pancreas,
and is located in the head of the pancreas.
Pancreatectomy, partial or complete, is complex
surgery with significant risks and consequences
(including DIABETES). It is a viable option only
when the surgeon is reasonably certain it will
completely remove the cancer. About 90 percent
of pancreatic cancers have metastasized by the
time of diagnosis. CHEMOTHERAPY may be effective
in achieving REMISSION. External beam RADIATION
THERAPY can shrink the cancer to relieve symptoms.
There are few clear risk factors or screening
procedures for pancreatic cancer. There is some
evidence of a hereditary component to pancreatic
cancer, as it appears to run in families, though
researchers have yet to detect the responsible
genes. In people at high risk for developing pancreatic
cancer because of family history, some cancer
experts suggest annual ENDOSCOPIC RETROGRADE
CHOLANGIOPANCREATOGRAPHY (ERCP). This endoscopic
procedure allows the gastroenterologist to examine
the pancreatic duct for signs of precancerous
changes in the cells (DYSPLASIA). Areas of focus
in research include GENE THERAPY and
IMMUNOTHERAPY (also called biological therapy),
though therapeutic application of these remains
investigational.
See also CANCER TREATMENT OPTIONS AND DECI-
SIONS; ENDOSCOPY; LYMPH NODES; PANCREATITIS; RISK
FACTORS FOR CANCER; STOMACH CANCER; SURGERY BENE-
FIT AND RISK ASSESSMENT.
pancreatitis INFLAMMATION of the PANCREAS that
can be acute (comes on suddenly) or chronic
(ongoing).
Acute pancreatitis can be life-threatening
and requires emergency medical
treatment.
Between them, excessive ALCOHOL consumption
and gallstones account for more than 80 percent
of pancreatitis. Other causes include CYSTIC
FIBROSIS, viral INFECTION (notably with the MUMPS
VIRUS), SIDE EFFECTS of certain medications, and
trauma to the abdomen (particularly blunt trauma
such as might occur in MOTOR VEHICLE ACCIDENTS). A
good deal of the time doctors cannot identify the
cause of pancreatitis.