Accurate assessment of mediastinal lymph nodes (MLN) is vital to optimizing treatment of lung cancer patients. Often currently available strategies fail to identify patients with advanced mediastinal disease. Accurate diagnosis of advanced nonsmall cell lung cancer (NSCLC) is critical to appropriate treatment with neoadjuvant therapy. We prospectively compared two promising new modalities, positron emission tomography (PET) and endoscopic ultrasound (EUS), for staging MLN in NSCLC.
From May 2004 to January 2005, Minneapolis VA Medical Center patients with known or suspected NSCLC, who were considered suitable candidates for surgical resection, were enrolled in the study. Prospectively, data was collected for subjects who underwent both PET and EUS as part of the preoperative evaluation. Outcomes were analyzed by tissue confirmation of diagnosis or serial imaging follow-up.
56 eligible patients were enrolled, with complete data available for 53. Final diagnosis was based on tissue in 47 subjects and on serial imaging in 6 subjects. PET imaging correctly diagnosed MLN status in 75% of subjects, while EUS guided fine-needle-aspiration was correct in 94% of subjects (difference 18.7%, p = 0.012, 95% CI 4.8% - 31.6%). Over all sensitivity, specificity and accuracy of PET were 60%, 92% and 75%; compared with 89%, 100% and 94% for EUS. We estimated that EUS obviated a surgical procedure in 54% (95% CI, 41.20% - 73.08%) of patients with enlarged MLN, and in 28% (95% CI, 10.37 % - 46.77%) of patients without suspicious nodes on imaging studies.
EUS guided fine-needle-aspiration was more accurate than positron emission tomography in staging MLN in lung cancer patients. EUS offers histologic confirmation of NSCLC involvement of MLN and allows a more appropriate utilitzation of neoadjuvant therapies.
The inclusion of EUS for preoperative staging of NSCLC allows for neoadjuvant therapy to be instituted without a surgical procedure being performed in the mediastinum. Mediastinoscopy can then be used for restaging patients following adjuvant treatment and reserve surgical resection for those patients that truly have a significant response to treatment.
Rosemary Kelly, None.