Current Concepts in the Mediastinal Lymph Node Staging of Nonsmall Cell Lung Cancer

Abstract
To review the current concepts in the mediastinal staging of nonsmall cell lung cancer (NSCLC), evaluating traditional and modern staging modalities. Staging of NSCLC includes the assessment of mediastinal lymph nodes. Traditionally, computed tomography (CT) and mediastinoscopy are used. Modern staging modalities include magnetic resonance imaging (MRI), positron emission tomography (PET), and endoscopic ultrasound with fine-needle aspiration (EUS-FNA) Literature was searched with PubMed and SUMSearch for original, peer-reviewed, full-length articles. Studies were evaluated on inclusion criteria, sample size, and operating characteristics. Endpoints were accuracy, safety, and applicability of the staging methods. CT had moderate sensitivities and specificities. With few exceptions magnetic resonance imaging (MRI) offered no advantages when compared with CT, against higher costs. PET was significantly more accurate than CT. Mediastinoscopy and its variants were widely used as gold standard, although meta-analyses were absent. Percutaneous transthoracic needle biopsy (PTNB) and transbronchial needle biopsy (TBNA) were moderately sensitive and specific. EUS-FNA had high sensitivity and specificity, is a safe and fast procedure, and is cost-effective. EUS-FNA evaluates largely a nonoverlapping mediastinal area compared with mediastinoscopy. PET has the highest accuracy in the mediastinal staging of NSCLC, but is not generally used yet. EUS-FNA has the potential to perform mediastinal tissue sampling more accurate than TBNA, PTNB, and mediastinoscopy, with fewer complications and costs. Although promising, EUS-FNA is still experimental. Mediastinoscopy is still considered as gold standard for mediastinal staging of NSCLC.