Pancreatic Adenocarcinoma: Update on Neoadjuvant and Adjuvant Treatment
- What is the approach to diagnosis and staging?
History and physical examination findings are not sufficiently sensitive or specific to diagnose pancreatic cancer. High clinical suspicion in a patient with risk factors can lead to a comprehensive evaluation and potential early diagnosis. In general, an initial diagnostic work-up for suspected pancreatic cancer will include serologic evaluation (liver function test, lipase, tumor markers) and abdominal imaging (ultrasound, CT scans, or magnetic resonance imaging [MRI]). Ultrasound is a first-line diagnostic tool with a sensitivity of 90% and specificity of 98.8% for pancreatic cancer, but it is investigator-dependent and is less accurate in detecting tumors smaller than 3 cm in diameter.19 Multiphasic helical CT of the abdomen has better sensitivity (100%) and specificity (100%) for detecting tumors larger than 2 cm, but this modality is less accurate in detecting pancreatic masses smaller than 2 cm (77%).20 Percutaneous fine-needle aspiration (FNA) performed by ultrasound or CT guidance is avoided due to theoretical concerns about intraperitoneal seeding and bleeding.
If a pancreatic mass is detected by ultrasound or CT, additional interventions may be indicated depending on the clinical scenario. EUS-guided biopsy can provide histological confirmation and is currently utilized frequently for diagnosis and early resectability staging. Endoscopic retrograde cholangiopancreatography (ERCP) is indicated for patients with biliary obstruction requiring stent placement, and this procedure may provide tissue confirmation by forceps biopsy or brush cytology (lower accuracy than EUS). In a meta-analysis that evaluated the diagnostic value of tests for pancreatic cancer, ERCP had the highest sensitivity (92%) and specificity (96%) compared to ultrasound and CT,21 but this modality carries a risk for pancreatitis, bleeding, and cholangitis. Magnetic resonance cholangiopancreatography has not replaced ERCP, but it but may be an alternative for patients who cannot undergo ERCP (eg, gastric outlet obstruction, duodenal stenosis, anatomical surgical disruption, unsuccessful ERCP). ERCP is used frequently because many patients present with obstructive jaundice due to pancreatic mass compression, specifically if the mass is located in the head, and must undergo ERCP and stenting of the common bile duct.
The carbohydrate antigen (CA) 19-9 level has variable sensitivity and specificity in pancreatic cancer, as levels can be elevated in many benign pancreaticobiliary disorders. Elevated CA 19-9, in the appropriate clinical scenario (ie, a suspicious pancreatic mass and a value greater than 37 U/mL) demonstrated a sensitivity of 77% and specificity of 87% when differentiating pancreaticobiliary cancer from benign clinical conditions such as acute cholangitis or cholestasis.22 CA 19-9 level has prognostic value, as it may predict occult disease and correlates with survival rates, but no specific cutoff value has been established to guide perioperative therapy for high-risk resectable tumors.23
The American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) tumor, node, metastasis (TNM) system is the preferred method for staging pancreatic cancer (Table 1). 
Positron emission tomography with CT scan is occasionally utilized in practice to assess tumor burden by evaluating anatomical structures and assessing physiologic uptake, which aids in establishing the extent of disease in equivocal cases. Staging laparoscopy with or without peritoneal biopsy is sometimes used to establish appropriate staging in cases that are questionable for occult metastatic disease. This procedure helps avoid unnecessary morbid surgeries.
