Nonsurgical treatments for submucosal esophageal squamous cell carcinomas

Abstract

Esophageal cancer is a disease with a poor prognosis. As with superficial esophageal cancers, lymph node metastases are seen rarely if the tumors are limited to the epithelium or lamina propria, but when cancers invade the submucosa, there is a high incidence of lymph node involvement. Surgery with radical lymph node dissection is a standard treatment for treating submucosal esophageal cancers. However, it is usually associated with a reduced level of quality of life for the patients, who are often elderly and have various medical complications making them unfit for aggressive surgery. According to these background indications, various nonsurgical treatments have been developed to preserve the esophagus and to achieve a less invasive cure for such patients. Definitive radiotherapy could be a treatment option for patients with superficial carcinomas, particularly for those with mucosal cancers with an unresectable width by endoscopic mucosal resection (EMR). Although there have been some retrospective analyses with a small number of patients, they could not draw definitive conclusions. Definitive chemoradiotherapy has become one of the treatment options for patients who desire nonsurgical treatment. It has shown similar survival rates with those seen for radical surgery in two retrospective analyses and one multicenter prospective phase II study. The combination of primary EMR and prophylactic chemoradiotherapy has also shown promising results with less invasiveness than surgery. These nonsurgical approaches are now under evaluation in two multi-institutional studies run by the Japan Clinical Oncology Group (JCOG), which will clarify the optimal treatment for this disease.