Current status and issues in genomic analysis using EUS-FNA/FNB specimens in hepatobiliary-pancreatic cancers

Abstract

Comprehensive genomic profiling based on next-generation sequencing has recently been used to provide precision medicine for various advanced cancers. Endoscopic ultrasound (EUS)-guided fine-needle aspiration (EUS-FNA) and EUS-guided fine-needle biopsy (EUS-FNB) play essential roles in the diagnosis of abdominal masses, mainly pancreatic cancers. In recent years, CGP analysis using EUS-FNA/FNB specimens for hepatobiliary-pancreatic cancers has increased; however, the success rate of CGP analysis is not clinically satisfactory, and many issues need to be resolved to improve the success rate of CGP analysis. In this article, we review the transition from EUS-FNA to FNB, compare each test, and discuss the current status and issues in genomic analysis of hepatobiliary-pancreatic cancers using EUS-FNA/FNB specimens.

Keywords: Comprehensive genomic profiling; EUS-guided fine-needle aspiration; EUS-guided fine-needle biopsy; Endoscopic ultrasound; Hepatobiliary–pancreatic cancers.

Fig. 1

Representative gene mutations in hepatobiliary–pancreatic cancers. Driver and actionable mutations are listed in red and blue, respectively. HCC hepatocellular carcinoma, IHCC intrahepatic cholangiocarcinoma, GBC gallbladder carcinoma, EHCC extrahepatic cholangiocarcinoma, PanNEC pancreatic neuroendocrine carcinoma, IPMC intra-ductal papillary mucinous carcinoma, PC pancreatic cancer

Fig. 2

Comparison of the representative EUS-FNB and EUS-FNA specimens in the same patient with pancreatic cancer. A 22-mm pancreatic cancer lesion was punctured with a 22-gage FNB and FNA needle. (a: Left upper) The EUS-FNB specimen obtained using a 22-gage FNB tri-tip core needle revealed multiple histological tissues. (b: Right upper) The tissue microfragment with intact tissue architecture was diagnosed as moderately differentiated pancreatic adenocarcinoma. These FNB specimens contributed to the suitability of CGP analysis. (c: Left bottom) The EUS-FNA specimen obtained using a 22-gage FNA lancet needle did not include tissue microfragments. (d: Left bottom) Most characteristic specimens showed blood clots. A sufficient number of tumor cells was not observed. Tumor cellularity of the specimens was 10% (88/892 cells) and 50% (618/1247 cells) for EUS-FNA and EUS-FNB, respectively. Very little tissue was collected by EUS-FNA, and most of the nucleated cells were neutrophils in the peripheral blood. Although pancreatic cancer was diagnosed, we speculated that CGP analysis of these specimens was impossible and/or unsuitable. EUS-FNA specimens sometimes include tissues, making it possible to perform CGP analyses. EUS endscopic ultrasound, FNA fine-needle aspiration, FNB fine-needle biopsy, CGP comprehensive genomic profiling