Diagnostic testing for suspected pancreatic cancer

Diagnostic testing for suspected pancreatic cancer

A 65-year-old man is evaluated in clinic for 1 month of progressive painless jaundice and a 10-lb unintentional weight loss. His physical examination is unremarkable. A dual-phase contrast CT shows a suspicious mass in the head of the pancreas with biliary ductal dilation. Which of the following is the best diagnostic test to evaluate for suspected pancreatic cancer? 

A. CT-guided percutaneous needle biopsy 

B. Endoscopic ultrasound–guided needle biopsy 

C. Endoscopic retrograde cholangiopancreatography with pancreatic juice sampling for cytopathology 

D. FDG-PET imaging 

E. Serum CA 19-9 

The answer is B. (Chap. 79) Dual-phase, contrast-enhanced spiral CT is the imaging modality of choice to visualize suspected pancreatic masses. In addition to imaging the pancreas, it also provides accurate visualization of surrounding viscera, vessels, and lymph nodes. In most cases, this study can determine surgical resectability. There is no advantage of MRI over CT in predicting tumor resectability, but selected cases may benefit from MRI to characterize the nature of small indeterminate liver lesions and to evaluate the cause of biliary dilatation when no obvious mass is seen on CT. Preoperative confirmation of malignancy is not always necessary in patients with radiologic appearances consistent with operable pancreatic cancer. Endoscopic ultrasound–guided needle biopsy is the most effective technique to evaluate the mass for malignancy. It has an accuracy of approximately 90% and has a smaller risk of intraperitoneal dissemination compared with CT-guided percutaneous biopsy. Endoscopic retrograde cholangiopancreatography is a useful method for obtaining ductal brushings, but the diagnostic value of pancreatic juice sampling is only 25%–30%. CA 19-9 is elevated in approximately 70%–80% of patients with pancreatic carcinoma but is not recommended as a routine diagnostic or screening test because its sensitivity and specificity are inadequate for accurate diagnosis. Preoperative CA 19-9 levels correlate with tumor stage and prognosis. They are also an indicator of asymptomatic recurrence in patients with completely resected tumors. FDG-PET should be considered before surgery for detecting distant metastases.