COMMENTARY

Endoscopic Ultrasound-Guided Fine-Needle Aspiration in the Diagnosis and Staging of Pancreatic Adenocarcinoma

Kyung W. Noh, MD; Michael B. Wallace, MD, MPH

Disclosures

May 25, 2005

In This Article

Introduction

Pancreatic cancer is the fourth leading cause of cancer-related deaths in the United States. According to the American Cancer Society, an estimated 32,180 individuals in the United States will be diagnosed with pancreatic cancer in 2005.[1] This disease is associated with a high mortality rate; the 5-year survival rate is estimated to be 4%. Currently, surgical resection is the only option for a cure. Unfortunately, due to its late presentation, resection is possible in only 15% of cases of pancreatic cancer. Even in this population, the 5-year survival rate is approximately 20%.[2,3] When disease is unresectable, chemotherapy, radiation therapy, or a combination of these modalities may be used to increase overall quality of life. Careful preoperative staging is paramount in the determination of optimal treatment, surgical intervention, or palliation of these patients. The primary goals of staging are to identify patients likely to benefit from surgery (by complete, margin-negative resection), provide prognostic information, and to obtain a tissue diagnosis in patients unsuitable for surgery or when otherwise needed.

The regional anatomy of the pancreas is complex, making procurement of cytologic samples historically difficult without exploratory laparotomy. Traditionally, computed tomography (CT) or endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been used to obtain biopsies of the pancreas. However, not all lesions are accessible due to surrounding organs and vasculature. Additionally, these techniques are associated with a risk of peritoneal dissemination of cancer cells and have a false-negative rate of up to 20%.[4,5] Endoscopic retrograde cholangiopancreatography (ERCP) brush cytology has a false-negative rate of at least 30%.[6]

EUS was developed in the 1980s to improve the imaging of the pancreas. Traditional transabdominal ultrasound imaging of the pancreas is hampered by intervening bowel gas, bone, and fat. By placing a high-frequency transducer directly within the stomach or duodenal lumen, EUS can obtain a detailed image of the pancreas that has a higher resolution than CT scan or magnetic resonance imaging, but with a much narrower field of view. These high-resolution images allow for identification of lesions as small as 2-3 mm and involvement of adjacent vascular structures.

This report specifically addresses the role of EUS-FNA in the detection and confirmation of pancreatic cancer.

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