Endobronchial and transesophageal endoscopic ultrasound-guided fine-needle aspiration are more sensitive than traditional transbronchial needle aspiration, a new study suggests. In the February 6 issue of the Journal of the American Medical Association, researchers show that combining these 2 newer biopsy methods achieves near-complete minimally invasive mediastinal staging in patients with suspected lung cancer.
The American College of Chest Physicians recommends invasive staging with tissue confirmation of suspected metastatic mediastinal lymph nodes. Mediastinoscopy or thoracoscopy has been the diagnostic standard, but less invasive methods have emerged as potential alternatives.
Noninvasive staging with chest computed tomography (CT) or positron emission tomography (PET) are examples, but, researchers note, CT is associated with high rates of false positives and PET is associated with high rates of false negatives.
Newer methods include blind transbronchial needle aspiration, endoscopic ultrasound-guided fine-needle aspiration, and the transesophageal version of this procedure.
Investigators, led by Michael Wallace, MD, from the Mayo Clinic in Jacksonville, Florida, hypothesized that newer endobronchial and transesophageal procedures would be more accurate than transbronchial needle aspiration. They also anticipated that the combination of the 2 ultrasound-guided procedures would provide complementary and complete staging of the mediastinum.
Combining 2 Procedures Eliminates Blind Spots
The procedures are typically limited by blind spots, but used together, specialists report they can see the entire area. “It is a disadvantage that patients require 2 procedures rather than just 1,” Dr. Wallace told Medscape Oncology. “But we found that all of our 138 patients really benefited from both. Moving forward, it will be interesting to define which patients might be able to have just 1 procedure.”
Dr. Wallace said the endobronchial and transesophageal procedures offer an exciting outpatient alternative. It is “typically a 1-hour procedure, and patients require only twilight sedation and can return home shortly after.”
Of the 138 patients with suspected lung cancer in the study who met all study criteria, 42 (30%) had malignant lymph nodes. The researchers found that the endobronchial procedure was more sensitive than blind transbronchial needle aspiration, detecting 69% vs 36% of malignant lymph nodes (P = .003).
The combination of the endobronchial and transesophageal procedures had higher estimated sensitivity (93%; 95% CI, 81% – 99%) and negative predictive value (97%; 95% CI, 91% – 99%) than either method alone.
The 2 procedures also had higher sensitivity and higher negative predictive value for detecting lymph nodes in any mediastinal location and for patients without lymph-node enlargement on chest CT.
Shifting From Organ-Based to Disease-Based Specialization
If mediastinoscopy had been performed only when results from the endobronchial and transesophageal procedures were negative, this surgical procedure would have been avoided in 28% of patients in this study, the authors write. If the procedures had been used to completely replace mediastinoscopy in all patients, 97% would have been correctly labeled as negative.
Dr. Wallace pointed out to Medscape Oncology that the findings need to be confirmed by other studies but appear to provide a promising alternative. He noted, however, that the high level of expertise of the Mayo specialists involved in the study might not be immediately replicated at other centers.
“We were able to set up a close collaboration of experts, and our gastroenterologists and pulmonologists were able to work together; this was important,” Dr. Wallace said. “Our program is well integrated.”
Dr. Wallace said that this will be important for other centers as well, but he anticipates that a shift will take place in the field, with an increased emphasis on minimally invasive biopsies for patients with suspected lung cancer.
“I think we’re going to start seeing more interventionalists specializing in minimally invasive techniques,” he said. “I think there will be more surgeons specializing in a couple of these procedures. We are moving from organ-based to more disease-based specialization, and we see evidence of this in the emergence of things like comprehensive cancer centers.”
This study was funded by the National Cancer Institute and by the James and Esther King Foundation of the State of Florida Department of Health. Equipment was provided by Olympus Corporation, in Center Valley, Pennsylvania. Dr. Wallace reports receiving research grants from Olympus, Fujinon, and Cook Co — makers of endoscopic ultrasound equipment.
JAMA. 2008; 299:540-546. Abstract
Allison Gandey is a journalist for Medscape. She is the former science affairs analyst for the Canadian Medical Association Journal. Allison, who has a master of journalism specializing in science from Carleton University, has edited a variety of medical association publications, and has worked in radio and television. She can be contacted at [email protected].
