Diagnostic Accuracy of Mediastinal Lymph Node Staging Techniques in the Preoperative Assessment of Nonsmall Cell Lung Cancer Patients

Background: Nonsmall cell lung cancer (NSCLC) treatment is based on an accurate staging. Mediastinal lymph nodes staging has a critical impact on treatment management. Methods: The objective was to assess the current accuracy of preoperative tools for predicting mediastinal and hilar lymph nodes staging with NSCLC. Retrospective analysis of 997 biopsy-proven NSCLC patients treated at a single academic medical center between January 2006 and April 2012. Mediastinal lymph nodes were evaluated with preoperatively with: computed tomography (CT), positron emission tomography (PET), endobronchial ultrasound-guided fine needle aspiration, and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Results are compared with pathologic surgical biopsy. Results: A total of 217 cervical mediastinoscopies, 15 anterior mediastinotomies, and 952 surgical lymphadenectomies were performed. The sensitivity of CT scan for mediastinal lymph nodes detection was 18.9% and PET-CT scan was 33.8%. Specificities were 94.9% and 93.8%, respectively. For hilar lymph nodes detection, CT was less sensitive (17.0% vs. 39.7%); however, more specific (94.7% vs. 80.3%) than PET-CT. Endobronchial ultrasound-guided fine needle aspiration (72.7% sensitivity and 100% specificity) and endoscopic ultrasound-guided fine needle aspiration (51.9% sensitivity and 100% specificity) both demonstrated superior results. Conclusions: The majority of biopsy-proven mediastinal lymph nodes metastases are not associated with positive results on preoperative CT or PET. CT and PET have low positive predictive value for mediastinal lymph node. This study supports the routine utilization of invasive mediastinal lymph nodes staging in NSCLC, especially for patients with tumors of >4 cm diameter, regardless of CT or PET-CT results.