ROLES AND PROBLEMS OF THE ENDOSCOPIC APPROACH FOR EARLY DIAGNOSIS OF PANCREATIC CANCER

Abstract

A long-term prognosis is expected in cases of PC < 1cm, and that dilatation of the pancreatic duct and the presence of a cystic lesion are important as indirect findings. When direct depiction of the tumor is difficult by ultrasonography (US) and dynamic multidetector computed tomography (MDCT), endoscopic ultrasonography (EUS) or magnetic resonance cholangiopancreatography (MRCP) should be performed.

The current clinical guidelines for pancreatic cancer (PC) in 2016 proposed that EUS-fine needle aspiration (FNA) should be performed when a mass lesion is detected by EUS and serial pancreatic juice aspiration cytologic examination (SPACE) should be performed when localized stenosis of the pancreatic duct, caliber change, and dilatation of the branch duct are found with endoscopic retrograde cholangiopancreatography (ERCP). Especially, SPACE is essential for diagnosis of PC in situ (PCIS). Recently, the Japan Study Group on the Early Detection of PC (JEDPAC) reported two hundred cases with Stage 0 and I. Image findings such as dilatation or irregular stenosis of the main pancreatic duct detected by CT, MRCP, or EUS were useful to detect early-stage PC. Preoperatively, SPACE followed by ERCP was more commonly applied than EUS-FNA. Recently, there have been some reports about tract seeding in the stomach after transgastric EUS-FNA. After performing SPACE, careful observation should be performed to avoid post-ERCP pancreatitis. The screening method including EUS for high-risk patients may be useful for the early diagnosis of PC. Some studies reported new diagnostic markers focusing on some genetic mutations or miRNAs in duodenal or pancreatic juice. From a recent prospective study, careful long-term follow-up including EUS should be performed in resected PC cases diagnosed at an early stage to check for recurrence in the remnant pancreas.