UAB Synopsis, Vol. 24, No. 21, June 6, 2005
For patients with non-small cell lung cancer (NSCLC), a recent UAB study showed transesophageal endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) added positive predictive value in determining the presence of cancer in posterior mediastinal lymph nodes and was a more effective staging tool than 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) or chest tomography (CT).
According to study lead author Mohamad Eloubeidi, MD, MHS, in the Annals of Thoracic Surgery (2005;79: 263-268), EUS-FNA tissue confirmation was 97% accurate and prevented surgical interventions for further staging in 57% of patients.
"Selecting the best treatment for patients with non-small cell lung cancer depends on accurately determining the stage of disease. Unfortunately, up to 40% of patients with lung cancer have mediastinal node involvement at diagnosis, which precludes surgical therapy," says Dr. Eloubeidi, who directs the UAB Endoscopic Ultrasound program. "These patients are best served by initial chemo-radiation therapy.
"Many patients with suspected non-small cell lung cancer are smokers, so large mediastinal nodes may indicate infection or causes other than cancer," he says. "Minimally invasive EUS-FNA makes it easier and more cost effective for us to evaluate and properly stage patients without surgical intervention."
Study coauthor and UAB Chief of Thoracic Surgery Robert Cerfolio, MD, says, "EUS-FNA is a highly accurate, minimally invasive tool that has revolutionized how we stage patients with non-small cell lung cancer prior to surgical resection." He has referred more than 700 patients for EUS-FNA. UAB cytopathologists subsequently make the diagnosis.
Unlike CT scans that rely primarily on node size to indicate possible cancer, PET scans rely on metabolic activity. While PET scans are superior to CT, neither provides tissue for definitive analysis.
Transesophageal endoscopic ultrasound, however, cannot image the anterior mediastinum and adjacent lymph nodes. A new endoscope under development called an endobronchial ultrasound may replace mediastinoscopy for evaluation of anterior lymph nodes.
"EUS-FNA complements other staging techniques. A safe, minimally invasive, accurate methodology, it provides tissue samples from suspicious posterior mediastinal lymph nodes detected by CT or PET scans," Dr. Eloubeidi concludes.