© 2005 American Thoracic Society
Endoscopic Ultrasound Staging of Lung CancerFrom the Authors:We would like to thank Dr. Wallace for his insightful comments regarding our study (1). The aim of our study was to determine the role of EUS and EUS-guided fine needle aspiration (EUS-FNA) in patients with nonsmall-cell lung cancer (NSCLC) without mediastinal lymphadenopathy who would otherwise proceed directly to surgery. We learned that mediastinal lymph node echocharacteristics are poor predictors of malignancy. In mediastinal lymph node regions accessible to EUS our sensitivity was 42%. We agree that tissue sampling of all mediastinal lymph nodes (malignant-appearing and benign-appearing) would likely result in a higher sensitivity of EUS in staging the mediastinum, as benign-appearing lymph nodes may harbor malignancy. Sampling of all mediastinal lymph nodes, however, increases procedure time, and we question the cost effectiveness as separate needles (approximately $200 each) would be required. It is interesting that despite differences in sensitivity, the detection rate of unresectable disease was 25% in both of our studies (1, 2). Further, metastases were found in regions that are not routinely interrogated during thoractomy (adrenal gland and celiac lymph nodes). We feel that recommendations on the utility of EUS in staging NSCLC with respect to tumor location are still premature, as tumor location may be a predictor of nodal metastases that can be sampled with EUS-FNA. Unlike Wallace and coworkers' recent study, we found that lower lobe and hilar tumors (versus left upper lobe tumors) were more likely to have metastases to mediastinal lymph nodes accessible to EUS. This is similar to unpublished data from the University of Alabama, Birmingham group, which showed that lower lobe tumors were six times more likely to have malignant mediastinal lymph nodes accessible to EUS-FNA compared with upper lobes (M.A. Eloubeidi, personal communication). It is our hypothesis that EUS-FNA could be directed toward patients with primary tumors in the lower and hilar lobes, and thus ultimately be cost effective in staging NSCLC. The standard of care in NSCLC staging is evolving, and certainly further studies examining the clinical and economic impact of EUS in staging NSCLC are needed so that management of patients with NSCLC is optimized.
Indiana University Medical Center, Indianapolis, Indiana FOOTNOTES Conflict of Interest Statement: J.K.L. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript. REFERENCES
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