Sentinel Lymph Node Mapping in Esophageal Cancer: Current Status and Future Directions

Abstract

Objective: This review provides a comprehensive discussion about the importance of adequate lymphadenectomy, its anatomic and oncologic significance, principles and rationale of sentinel lymph node mapping, current evidence stratified by tracer substrate, challenges, and future directions. Esophageal cancer has one of the worst cancer-related survival rates, and nodal status is the single most significant prognostic factor. Submucosal penetration generally demands esophagectomy, often following neoadjuvant therapy in the presence of deeper extension. Guidelines recommend resecting ≥15 lymph nodes. Variability in surgical approach and dissection in concert with aberrant esophageal lymphatic anatomy make adequate lymphadenectomy difficult.

Methods: A narrative review was conducted to explore existing literature regarding lymphadenectomy with its requisite anatomic and oncologic significance in esophageal cancer, as well as the rationale for and present state of sentinel lymph node mapping stratified by substrates. Tables and figures were constructed by the authors using Microsoft Office applications and Biorender software, respectively.

Results: Sentinel lymph node mapping exploits the tumoral lymphatic network to identify the nodes most prone to metastasis, directing further dissection. Targeting sentinel lymph nodes with dyes, radiotracers, or hybrid tracers can assist surgeons with lymphadenectomy, potentially improving staging accuracy and personalizing care to individual anatomy.

Conclusions: While this approach would benefit from larger studies and long-term data, early evaluations suggest improved detection of metastases outside the en bloc field without significantly increasing morbidity.

Keywords: Esophageal adenocarcinoma; Esophageal cancer; Esophageal squamous cell carcinoma; ICG; SLN; Sentinel lymph node; Sentinel lymph node mapping.