Role of endoscopic ultrasound in the diagnosis and staging of pancreatic cancer

Abstract

Early diagnosis of pancreatic cancer remains a difficult task, and multiple imaging tests have been proposed over the years. The aim of this review is to describe the current role of endoscopic ultrasound (EUS) for the diagnosis and staging of patients with pancreatic cancer. A detailed search of MEDLINE between 1980 and 2007 was performed using the following keywords: pancreatic cancer, endoscopic ultrasound, diagnosis, and staging. References of the selected articles were also browsed and consulted. Despite progress made with other imaging methods, EUS is still considered to be superior for the detection of clinically suspected lesions, especially if the results of other cross-sectional imaging modalities are equivocal. The major advantage of EUS is the high negative predictive value that approaches 100%, indicating that the absence of a focal mass reliably excludes pancreatic cancer. The introduction of EUS-guided fine needle aspiration allows a preoperative diagnosis in patients with resectable cancer, as well as a confirmation of diagnosis before chemoradiotherapy for those that are not. This comprehensive review highlighted the diagnostic capabilities of EUS including the newest refinements such as contrast-enhanced EUS, EUS elastography, and 3-dimensional EUS. The place of EUSguided biopsy is also emphasized, including the addition of molecular marker techniques.

Role of pancreatic endoscopic ultrasonography in 2010

“…Cancers of the pancreas are usually visualized on EUS as more or less well demarcated echo-poor lesions, which -depending on their exact morphology and size -are homogeneous or inhomogeneous, with echo-rich spots or even cystic spaces [30,31] . Small pancreatic cancers can also be visualized as echo-poor and well demarcated lesions, thus resembling pancreatic neuroendocrine tumors, or may display a pattern of focal inhomogeneity.…”

“…The major advantage of imaging by means of EUS for pancreatic cancer (even in the era of recent imaging advances) seems to be its high negative predictive value (NPV) [30] . Recent data support the evidence that, on EUS performed by an expert endosonographer, absence of a circumscriptive mass can reliably exclude pancreatic cancer, especially in the setting of a low or indeterminate pre-test probability.…”

“…119/135) no additional work-up was required [38] . When EUS is compared to other imaging modalities, although it is not a 100% foolproof method [39][40][41] , it still remains one of the best choices to detect a pancreatic neoplasm [30,35,42] . However, it should be emphasized that many of the studies comparing EUS and other crosssectional imaging techniques are characterized by the absence of blinding amongst examiners, and therefore an objective assessment of the superiority of one test over another is hard [43,44] .…”

“…Nevertheless, in the hands of an experienced examiner, transabdominal US can reveal direct or indirect signs of a pancreatic malignancy, i.e. direct, such as focal hypoechoic pancreatic mass, and indirect, such as a dilated CBD(> 7 mm) with or without a dilated pancreatic duct(> 2-3 mm), liver metastases or/and ascites [30,45,46] .…”

“…EUS-FNA in diagnosis of pancreatic cancer EUS-FNA has offered new potential to EUS, as it allows for transmural tissue diagnosis with minimum invasion. EUS-FNA can therefore be extremely useful for various indications, such as suspected pancreatic cancer, diagnosis of pancreatic carcinoma, or differential diagnosis of pancreatic mass or smaller lesions [30,36,43,[53][54][55][56][57] . The indications of EUS-FNA are quite controversial, except for cases where chemotherapy or radiotherapy is needed.…”