State-of-the-Art Mediastinal Staging in Non-Small-Cell Lung Cancer: Integration of Combined Endosonographic Techniques with Updated IASLC TNM 9th Classification

The objective of this review is to evaluate the role of combined endobronchial and esophageal endosonography in mediastinal staging and to define its clinical implications within the proposed IASLC TNM 9th edition framework. Mediastinal staging remains a critical step in the management of non-small cell lung cancer (NSCLC), as it directly impacts treatment planning, surgical decision-making, and overall prognosis. For many years, mediastinoscopy was considered the standard approach; however, in routine practice, it has largely been replaced by less invasive techniques. Endobronchial Ultrasound (EBUS) and Endoscopic Ultrasound (EUS) have become widely adopted because they allow real-time sampling of lymph nodes with good accuracy and a low complication rate. In clinical settings, these techniques are often used together rather than separately, as each provides access to different nodal stations. This combined approach improves diagnostic yield and reduces the number of patients who require surgical staging. At the same time, recent updates in the IASLC TNM classification, including the proposed 9th edition, have introduced more detailed nodal categories, making accurate tissue confirmation even more important in daily practice. In this review, we summarize the current use of combined EBUS and EUS in mediastinal staging, focusing on their practical advantages, limitations, and roles across different clinical scenarios. We also discuss their relevance in the context of molecular testing and evolving treatment strategies. Despite their strengths, there are situations in which negative results should be interpreted with caution and confirmed surgically. Overall, these techniques have reshaped the approach to mediastinal staging and are now central to modern lung cancer care.