Pancreatic Cancer - Causes, Symptoms & Treatment

Pancreatic cancer is the fourth most lethal of all carcinomas. It occurs most often among blacks, particularly in men between ages 35 and 70. Incidence of pancreatic cancer is highest in Israel, the United States, Sweden, and Canada and lowest in Switzerland, Belgium, and Italy. The prognosis is poor: Most patients die within 1 year of diagnosis.

Causes

Evidence suggests that pancreatic cancer is linked to inhalation or absorption of carcinogens that are then excreted by the pancreas. Examples of such carcinogens include:

• cigarette smoke (pancreatic cancer is three to four times more common among smokers)
• excessive fat and protein (a diet high in fat and protein induces chronic hyperplasia of the pancreas, with increased turnover of cells)
• food additives
• industrial chemicals, such as betanaphthalene, benzidine, and urea.

Other possible predisposing factors include chronic pancreatitis, diabetes mellitus, and chronic alcohol abuse.

Tumors of the pancreas are almost always adenocarcinomas. They arise most frequently (67% of the time) in the head of the pancreas. Tumors in this location commonly obstruct the ampulla of Vater and common bile duct and metastasize directly to the duodenum. Adhesions anchor the tumor to the spine, stomach, and intestines.

Less frequently, tumors arise in the body and tail of the pancreas. When this happens, large nodular masses become fixed to retropancreatic tissues and the spine. The spleen, left kidney, suprarenal gland, and diaphragm are directly invaded, and the celiac plexus becomes involved, resulting in splenic vein thrombosis and spleen infarction. Among the rarest of pancreatic tumors are islet cell tumors.

Signs and Symptoms

The following are the other most common symptoms of pancreatic cancer. However, each individual may experience symptoms differently. Symptoms may include:

• Diarrhea
• Loss of appetite
• Jaundice (yellowing of the skin and whites of the eyes).
• Indigestion
• Vomiting
• Fatigue
• Unexplained weight loss.

The symptoms of pancreatic cancer may resemble other conditions or medical problems. Always consult your physician for a diagnosis.

Diagnostic tests 

Pancreatic cancer is usually discovered during the course of the evaluation of aforementioned symptoms. Liver function tests may show a combination of results indicative of bile duct obstruction (raised bilirubin , ?-glutamyl transpeptidase and alkaline phosphatase levels). Imaging studies, such as ultrasound or abdominal CT may be used to identify tumors. Endoscopic ultrasound (EUS) is another procedure that can help visualize the tumor and obtain tissue to establish the diagnosis.

Other laboratory tests that support the diagnosis include:

• serum amylase-lipase (occasionally increased)
• prothrombin time (prolonged)
• alkaline phosphatase (markedly elevated with biliary obstruction)
• hemoglobin and hematocrit (may show mild anemia)
• fasting blood glucose (may indicate hypoglycemia or hyperglycemia)
• stool studies (may show occult blood if ulceration in the GI tract or ampulla of Vater has occurred)

Treatment

Because pancreatic cancer may metastasize widely before it's diagnosed, treatment seldom succeeds in curing the disease. Treatment consists of surgery and, possibly, chemotherapy and radiation therapy.

Some surgical procedures help increase the survival rate slightly.

• Total pancreatectomy may increase survival time by resecting a localized tumor or by controlling post-operative gastric ulceration.
• Cholecystojejunostomy, choledochoduodenostomy, and choledochojejunostomy have partially replaced radical resection. They bypass the obstructing common bile duct extensions, easing jaundice and pruritus.
• If radical resection isn't indicated and duodenal obstruction is expected to develop later, a gastrojejunostomy is performed.

Whipple's operation, or radical pancreatoduodenectomy, has a high mortality rate but can obtain wide lymphatic clearance, except with tumors located near the portal vein, superior mesenteric vein and artery, and celiac axis. This seldom-used procedure removes the head of the pancreas; the duodenum; portions of the body and tail of the pancreas, stomach, jejunum, and pancreatic duct; and the distal portion of the bile duct.

Pancreatic cancer usually responds poorly to chemotherapy, but recent studies using combinations of fluorouracil, streptozocin, ifosfamide, and doxorubicin show a trend toward longer survival time.

Radiation therapy usually doesn't increase long­term survival, although it may prolong survival time from 6 to 11 months when used as an adjunct to fluorouracil chemotherapy. It also can ease the pain associated with nonresectable tumors.

Prevention

Because early detection is important in the treatment of pancreatic cancer, report any sudden weight loss, digestive problems, weakness, and lack of energy to your doctor. If you have been diagnosed with pancreatic cancer, follow your doctor's recommendations for diet, rest, and medical treatment. While the exact cause of pancreatic cancer is not known, you can lower your risk by eating a high fiber, low fat diet; exercising regularly; and avoiding smoking.