For the diagnosis and staging of gastrointestinal tract malignancies, the relative roles of fine needle aspiration (FNA) and fine needle biopsy (FNB) are being reevaluated.1 In endoscopic ultrasound (EUS)-guided acquisition of tissues, including esophageal, gastric, pancreaticobiliary, and rectal tissues among others, use of FNA remains a gold standard. That being said, core tissues obtained using FNB can offer an opportunity to evaluate cytology and histology, thus providing options for improved visualization (via staining, etc) and better assessment of tissue sample architecture.1,2

“For the majority of lesions that we’re accessing by EUS, the technique of FNA is adequate. However, we are seeing a growing number of indications where the added information from a core biopsy is essential for diagnosis and for guiding therapy,” said Christopher J. DiMaio, MD, Director of Therapeutic Endoscopy at the Icahn School of Medicine at Mount Sinai in New York City. Some studies have shown that dual FNA and FNB use may provide an added diagnostic utility versus use of each technology alone3 and that the accuracy of the two tools is comparable.4 However, more data describe the higher accuracy of FNB used alone in diagnosing certain lesions (ie, subepithelial masses) without additional rapid on-site cytology evaluation or other testing.5

Collecting adequate tissue for genetic tests also is becoming important for selecting targeted and individualized therapies for many tumors, such as those in the pancreas.6 “The role of personalized medicine in pancreatic cancer continues to evolve, and there is no doubt that the demand for core biopsies will continue to increase,” said Sachin Wani, MD, Assistant Professor in the Division of Gastroenterology and Hepatology at the University of Colorado Anschutz Medical Center, in Aurora, Colorado. At the Medical Center, investigators are “currently conducting several studies evaluating novel therapies in pancreatic cancer that mandate core pancreatic cancer specimens,” Dr. Wani added.

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An example of core tissue obtained using endoscopic ultrasound–guided fine needle biopsy.
Image courtesy of Petros Benias, MD, Director of Therapeutic Endoscopy and Assistant Professor of Medicine in the Division of Digestive Diseases at Mount Sinai Beth Israel in New York City.

Use of needles for biopsy is a centuries-old practice, while FNA specifically has been developed and crafted in more recent history, particularly the past 25 years.1,7 “The initial FNB devices became available in the 1990s, but they were not widely used. The needle was larger and the early core needles were cumbersome to use. As FNA was easier to employ and provided an adequate tissue sample in most cases, there was reluctance to accept a higher risk of complications,” said Douglas G. Adler, MD, Professor of Medicine in the Division of Gastroenterology and Hepatology at the University Of Utah School Of Medicine, in Salt Lake City, Utah. Also, use of early FNB devices lagged due to noted design limitations and a lack of flexibility and maneuverability, which limited the ability to obtain difficult-to-reach tissues. Modifications to these FNB devices, including the availability of various needle sizes, have sought to correct the perceived flaws of these early devices.1

Multiple manufacturers1 since have developed their own FNB devices and altered the device handles, needles, and access ports to EUS systems to ensure that tissue samples can be obtained efficiently while providing ease of use. One of the latest devices to gain regulatory approval,8 the SharkCore™ Fine Needle Biopsy needle—a newer-generation device used as part of the Beacon™ EUS Delivery System (Medtronic)—is the only FDA-cleared device of its kind on the market offering a safety sheath to help reduce the risk for needle sticks.9 Along with providing multiple needle sizes (19-, 22-, and 25-gauges9), as other devices have in the past, SharkCore can separate from the Beacon Delivery System, allowing for needle interchangeability when a different-sized needle is appropriate.

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Obtaining tissue samples using SharkCore™ Fine Needle Biopsy.
Image courtesy of Clarence KW Wong, MD, FRCPC, Associate Professor of Medicine at the University of Alberta and Gastroenterologist in the Division of Gastroenterology at Royal Alexandra Hospital in Edmonton, Alberta.

GI practitioners hoping for improved tissue acquisition have noticed updates to device technology: According to Dr. Adler, “the SharkCore device functions more like a FNA device, and it obtains core tissue samples about 80% of the time in our experience, which is higher than we have seen previously. The ease of use is an advantage but cost cannot be ignored. FNB is more expensive than FNA, so these are not used interchangeably.”

Robert M. Najarian, MD, Gastrointestinal, Liver, and Pancreatic Pathologist at Beth Israel Deaconess Medical Center in Boston, Massachusetts, shared his perspective. Dr. Najarian suggested that FNA is less expensive and often provides adequate tissue, but the improving yields from new-generation EUS-guided FNB devices have the potential to expand indications for this approach. One example is the use of FNB in relatively small lesions with the potential of an indeterminate cytological yield. “If FNB provides an adequate core biopsy, surgery can proceed based on predetermined goals rather than a presumptive diagnosis,” Dr. Najarian explained. “The yield with the newer FNB devices is very good, and FNB in many cases can reduce the risk of a false-negative result.”

The skills to achieve a high yield from FNB are generally transferable from FNA, according to the interviewed experts. All agreed that trainees should gain expertise with both. “It is important for any trainee to be able to perform both FNA and FNB, to understand when one technique may be preferred (or necessary) over the other, and to understand the diagnostic and economic aspects of each of these approaches when deciding which technique to utilize,” Dr. DiMaio said. FNB may provide more valuable diagnostic information in a variety of specific situations, such as autoimmune pancreatitis and suspected lymphomas, Dr. DiMaio said. Also, “FNB is a valuable salvage technique when FNA fails,” he added. A technical review by the American Society for Gastrointestinal Endoscopy also recommends FNB in the event of FNA failure.1

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Tissue obtained for determining pancreatic adenocarcinoma diagnosis using 22-gauge SharkCore™ Fine Needle Biopsy.
Image courtesy of Petros Benias, MD, Director of Therapeutic Endoscopy and Assistant Professor of Medicine in the Division of Digestive Diseases at Mount Sinai Beth Israel in New York City.

Clinicians also are seeking core biopsies to provide tissue for analyzing the mutation status of a tumor—a step needed for selecting targeted therapy. “Tissue samples are increasingly required for participation in clinical trials for cancer therapies,” said Dr. Najarian, referring specifically to studies testing novel therapies in pancreatic cancer. While he too suggested that FNA remains the gold standard for most EUS-guided tissue acquisition in the GI tract, he agreed that simpler, newer, and more reliable devices are likely to expand indications for FNB.

References

  1. Wani S, Muthusamy VR, Komanduri S. EUS-guided tissue acquisition: an evidence-based approach (with videos). Gastrointest Endosc. 2014;80(6): 939-959.e7.
  2. Attili F, Capurso G, Vanella G, et al. Diagnostic and therapeutic role of endoscopy in gastroenteropancreatic neuroendocrine neoplasms. Dig Liver Dis. 2014;46(1):9-17.
  3. Soh JS, Lee HS, Lee S, et al. The clinical usefulness of endoscopic ultrasound-guided fine needle aspiration and biopsy for rectal and perirectal lesions. Intest Res. 2015;13(2):135-144.
  4. Lin M, Hair CD, Green LK, et al. Endoscopic ultrasound-guided fine-needle aspiration with on-site cytopathology versus core biopsy: a comparison of both techniques performed at the same endoscopic session. Endosc Int Open. 2014;2(4):E220-E223.
  5. Keswani RN, Krishnan K, Wani S, et al. Addition of endoscopic ultrasound (EUS)-guided fine needle aspiration and on-site cytology to EUS-guided fine needle biopsy increases procedure time but not diagnostic accuracy. Clin Endosc. 2014;47(3):242-247.
  6. Bournet B, Gayral M, Torrisani J, et al. Role of endoscopic ultrasound in the molecular diagnosis of pancreatic cancer. World J Gastroenterol. 2014;20(31):10758-10768.
  7. Diamantis A, Magiorkinis E, Koutselini H. Fine-needle aspiration (FNA) biopsy: historical aspects. Folia Histochem Cytobiol. 2009;47(2):191-197.
  8. Food and Drug Administration. SharkCore™ Fine Needle Biopsy System 510(k) premarket notification (K141894). www.accessdata.fda.gov/​cdrh_docs/​pdf14/​K141894.pdf. Accessed October 14, 2015.
  9. Beacon Endoscopic. SharkCore™ Fine Needle Biopsy. www.beaconendoscopic.com/​sharkcore-fine-needle-biopsy. Accessed October 14, 2015.