Chapter 26-13: Pancreatic Cancer

TEXTBOOK PRESENTATION

Patients with pancreatic cancer often have vague abdominal pain for weeks or months, followed by weight loss and perhaps the abrupt onset of painless jaundice.

DISEASE HIGHLIGHTS

1. > 90% of cases are ductal carcinomas; 60–70% are in the pancreatic head, 20–25% in the body or tail, and 10–20% involve the whole organ

2. Risk factors

   1. Smoking (related in up to 20% of cases) and family history of pancreatic cancer (present in 7–10% of patients) are the most important risk factors.

   2. Other risk factors include the following:

      1. Family history of chronic pancreatitis, older age, male sex, African-American ethnic origin

      2. Diabetes, obesity

      3. Non-O blood group

      4. Occupational exposures (chlorinated hydrocarbon solvents and nickel)

      5. High fat diet; high meat/low vegetable diet

3. Clinical presentation

   1. Symptoms are insidious and often present for more than 2 months; depression is the first symptom in 38–45% of patients.

   2. Abdominal pain and weight loss are common presenting complaints, occurring in 80% and 85% of patients, respectively.

   3. Back pain is prominent if splanchnic nerve or celiac plexus infiltration occurs.

   4. Jaundice

      1. 80% of patients with cancers in the head; more if mass is > 2 cm

      2. Can occur when the cancer is in the body but is then due to liver metastases

      3. Can be painless or associated with abdominal pain

   5. Less common presentations include acute pancreatitis, malabsorption, migratory thrombophlebitis, and gastrointestinal bleeding.

   6. Intraductal papillary mucinous neoplasms (IPMN), a potential precursor lesion of pancreatic ductal carcinomas, are increasingly being detected incidentally on abdominal imaging.

      1. Histopathologic evaluation, usually through endoscopic ultrasound and fine-needle aspiration, in addition to imaging is critical for identifying high-risk lesions that can inform treatment decisions.

         1. IPMN lesions < 10 mm in size can be monitored with surveillance imaging.

         2. Those > 30 mm in size or with high-risk MRI characteristics should be biopsied.

         3. The approach to those between 10 mm and 30 mm in size is unclear.

      2. If pancreatic cancer develops, the 5-year survival is ∼50%, which is much higher than ductal adenocarcinoma.

EVIDENCE-BASED DIAGNOSIS

1. The first imaging study in most patients presenting with jaundice is an ultrasound.

   1. Sensitivity, 75–89%; specificity, 90–99%

   2. The sensitivity may be less in obese patients or with less experienced sonographers.

2. If the ultrasound shows a pancreatic mass, the next test should be a triphasic pancreatic-protocol multidetector CT.

   1. Sensitivity, 86%; specificity, 90%; LR+, 8.6; LR–, 0.16

   2. Sensitivity lower for cancers < 2 cm (77%) compared with those > 2 cm (89%)

   3. Best test for determining potential resectability

3. If an initial ultrasound does not show a mass, pancreatic protocol CT, magnetic resonance cholangiopancreatography (MRCP), endoscopic ultrasound (EUS), or endoscopic retrograde cholangiopancreatography (ERCP) should be done.

   1. MRCP is noninvasive with similar sensitivity and specificity to pancreatic protocol CT.

   2. EUS requires endoscopy but does not lead to as many complications as ERCP; sensitivity, 94%; specificity, 89%; LR+, 8.5; LR–, 0.06.

   3. ERCP is invasive and has a sensitivity of only 50–60% for detecting pancreatic cancer, with a specificity of 94%; ...