Endoscopic Ultrasound in Squamous Cell Esophageal Cancer: From Staging to Strategy-A Narrative Review

Esophageal squamous cell carcinoma (ESCC) remains a major global health challenge due to its aggressive nature and frequent late-stage diagnosis. Accurate locoregional staging is critical for guiding appropriate therapy, and endoscopic ultrasound (EUS) has emerged as the preferred modality for assessing tumor depth and regional lymph node involvement. In this narrative review, we provide a comprehensive overview of the role of EUS in the management of ESCC, from initial staging to post-treatment assessment. We discuss its strengths and limitations, particularly in differentiating early-stage disease and in restaging after neoadjuvant therapy. The importance of a multimodal approach-integrating EUS with computed tomography (CT), positron emission tomography (PET), and histologic sampling-is emphasized to improve diagnostic precision. We also explore emerging techniques, such as contrast-enhanced EUS, elastography, and novel therapeutic strategies including immune checkpoint inhibitors and endoscopic mucosal resurfacing. While EUS remains a cornerstone in the management of ESCC, ongoing innovation and integration with personalized medicine are expected to further enhance its clinical impact.