Treatment strategy for early-stage esophageal cancer.

Approximately 90% of esophageal cancers in Japan are squamous cell carcinomas, and they are often detected at earlier stages in Japan than in Western countries; superficial esophageal cancer without lymph node or distant metastasis comprises one-third of all esophageal cancers in Japan. Endoscopic resection is a minimally invasive treatment for superficial esophageal cancer; however, the risk of regional lymph node recurrence is negligible when it invades the submucosal layer or lymphovasculature. In such cases, surgical treatment is necessary to control regional lymph node recurrences, although the physical burdens and potential complications cannot be overlooked. Recently, clinical trials in Japan have shown promising clinical outcomes of organ preservation strategies. One strategy is initially performing endoscopic resection for superficial esophageal cancer, assessing the risk of lymph node metastasis based on pathological diagnosis for endoscopically resected specimens, and subsequently considering additional therapy (e.g., observation or prophylactic chemoradiotherapy)-another strategy aimed to cure superficial esophageal cancer through definitive chemoradiotherapy alone. The safety and efficacy of the two strategies have been evaluated in clinical trials, which showed that both organ preservation strategies are comparable to surgery in terms of overall survival. However, challenges include improving the accuracy of pretreatment endoscopic diagnosis and decreasing the local-regional recurrence after chemoradiotherapy. This review provides an overview of the latest standard treatment for early-stage esophageal cancer and its future perspectives.