Abstract
Chemoradiotherapy (CRT) or radiotherapy (RT) is a potential optional therapy for esophageal squamous cell carcinoma, because radiation-based therapy is conservative and less invasive. However, radiation-based therapy for esophageal cancer is disadvantageous because of a high locoregional failure rate. Detecting small recurrent cancer at the primary site at the early stage is necessary for potential salvage treatment. Early primary-site recurrence of esophageal cancer after a complete response to radiation-based therapy is detectable with frequent endoscopic surveillance, especially during the two-year period after a complete response. The appearance of a submucosal tumor is a useful endoscopic sign of early recurrence.
Useful salvage therapies for recurrence lesion after radiotherapy include endoscopy-based therapy, endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD) and photodynamic therapy (PDT). The criteria for EMR/ESD are : 1) no deep ulcer, 2) clinically defined N0 and M0 by endoscopic ultrasound (EUS) and computed tomography (CT), 3) definite or suspected cancerous mass limited to the submucosa, and 4) an expectation that complete resection can be achieved by endoscopic resection. On the other hand, the criteria for PDT are : 1) clinically defined N0 and M0 by EUS and CT, 2) local failed lesion limited within the muscularis propria (T2), 3) patient refusal of salvage esophagectomy or lack of tolerability for salvage esophagectomy. Salvage therapy is performed on local failure lesions that meet at least one of the following criteria : a) histologically proven carcinoma by biopsy specimen, b) emerged ulceration in the lesions, c) enlarged submucosal tumor-like protrusion in the lesion, d) presence of a heteroechoic solid component on EUS observation.
