Photodynamic therapy and endoscopic mucosal resection as minimally invasive approaches for the treatment of early esophageal tumors: Pre-clinical and clinical experience in Lausanne

Esophageal cancer, when detected at an early stage, has a very good probability of being eradicated by surgery or radiotherapy. However, less aggressive treatments also tend to provide high rates of cure without the side effects of radical surgery or radiotherapy. Among them, photodynamic therapy and endoscopic mucosal resection have been experienced as alternative techniques for mucosal ablation in patients with superficial squamous-cell carcinoma (SCC) of the esophagus, or high-grade dysplasia and early stage adenocarcinoma arising in Barrett's esophagus. We report on the results of our clinical experience with photodynamic therapy and discuss about its advantages and limitations. We also present a pre-clinical study, which had evaluated the feasibility, efficacy, and safety of a promising new method of endoscopic mucosal resection (EMR) based on the use of a modified rigid esophagoscope. The animal model chosen was the sheep because of its similarities with humans regarding the thickness and histologic structure of the esophagus. This new resection modality offers a promising approach in comparison with other options currently available, namely EMRs performed with flexible gastroscopes. It appears to be superior in terms of the size of the resected specimen, the precision and regularity of the resection depth, and the accuracy of histological diagnosis with safety margins.