Etiology and Pathogenesis:

Most pancreatic cancers arise from the cuboid epithelium of pancreatic ducts. The remaining 10% of pancreatic cancers include endocrine tumors, epidermoid cancers, adenoacanthomas, sarcomas, and cystadenocarcinomas. Approximately 2/3 of pancreatic cancers arise in the head of the pancreas. The remaining 1/3 arise in the body and tail.

Pancreatic cancer is a deadly disease. The median survival after diagnosis is 4 to 8 months and the 5-year survival rate is less than 1% in patients without tumor resection. In patients with tumor resection, the median survival after diagnosis is 17 to 20 months with a 5-year survival rate of less than 10%. Only breast, colorectal, lung, and prostate cancers are responsible for more cancer-related deaths.

Epidemiology:

The incidence of pancreatic cancer is approximately 12 per 100,000. Each year, approximately 27,000 Americans develop pancreatic cancer.
It occurs more frequently in men (3:2). It typically presents between the ages of 60 and 80. This disease is rare in people younger than 40 years. Risk factors for pancreatic cancer include hx of chronic pancreatitis, family hx of hereditary pancreatitis or non-polyposis colon cancer syndrome, smoking, heavy alcohol use, chemical exposure (e.g., benzidine, Beta-naphthylene), and diabetes mellitus.


Clinical Manifestations:

The signs and symptoms of pancreatic carcinoma are usually related to the location of the tumor. Patients with tumors in the head of the pancreas usually present with painless jaundice (80%), abdominal pain (90%), weight loss greater than 10% of ideal body weight (almost universal), weakness, pruritis, Courvoisier's sign, acholic stools (60%), dark urine, and mild glucose intolerance (up to 80%). The jaundice, Courvoisier's sign, acholic stools, and dark urine are due to obstruction of the common bile duct. The abdominal pain is typically described as persistent, aching, increased by lying supine or by eating, and causing the patient to awaken at night. Weight loss is due to both pancreatic insufficiency and anorexia. Glucose intolerance is due to increased plasma levels of islet amyloid polypeptide, causing insulin resistance. The diabetes is usually mild and fewer than 5% of patients have hyperphagia, polydipsia, and polyuria.

Patients with tumors in the body or tail of the pancreas usually present with weight loss and abdominal pain (90%); nausea and vomiting; and fatigue. Occasionally, patients can exhibit Trousseau's syndrome (migratory thrombophlebitis; 10%) or jaundice (less than 10%).


Diagnosis:

CT scan is the imaging modality of choice for diagnosing pancreatic cancer. It has a sensitivity of 79% and specificity of 64%. If a tumor is highly suspected but not found by CT scan, the most sensitive test is endoscopic US. Other imaging studies such as cholangiography (PTC or ERCP) and angiography can aid in the diagnosis and staging of the disease.
Laboratory findings can include elevated serum lipase, amylase, glucose, alkaline phosphatase, AST, ALT, bilirubin, and pancreatic tumor markers (CEA, CA 19-9). However these tests lack specificity.


Treatment:

Surgical resection of the pancreatic tumor offers the only chance for cure. The surgical procedure of choice is a pancreaticoduodenectomy. Adjuvant chemoradiation after tumor resection can prolong survival. The role of preoperative neoadjuvant chemoradiation is still under study.