E-Cadherin Is an Accurate Target for Fluorescence-Guided Imaging of Lymph Nodes.

Lymph node (LN) dissection is a necessary part of every oncologic surgery in order to provide important information for staging, predicting prognosis and improving survival. To do this, surgical oncologists strive to localize and dissect every pathologically positive LN while avoiding the increased morbidity of removing true negative LNs. The goal is to develop an imaging method to distinguish positive and negative LNs, but a specific biomarker is missing. Thus, our aim is to identify a reliable imaging marker for identifying LNs with lung cancer cells. After screening many epithelial markers, we identified E-cadherin, a membrane protein normally expressed in epithelial cells, including in the lung. To follow up on our potential target, we performed immunofluorescence staining on 48 human LNs with a conjugated anti-E-cadherin monoclonal antibody. Fluorescence was significantly higher in LNs with metastasis, as shown in 48 positive LNs from patients with resected primary lung cancer. There was high fluorescence in both hilar and mediastinal LNs, and in all primary tumor histologies. E-cadherin may be useful for the surgical oncologist for targeted imaging technologies for selecting positive LNs from lung cancer.