Proton beam therapy for esophageal cancer compared to existing treatments, including X-ray therapy and surgery

Esophageal cancer is one of the most difficult cancers to treat since it is often at an advanced stage at the time of symptom presentation. For locally advanced esophageal cancer, treatment options include multidisciplinary treatment such as surgery or definitive chemoradiotherapy. Surgery has a high local control rate because it involves excision of the cancer along with the surrounding organs; however, it is still highly invasive, although advances in surgery have reduced the burden on patients. On the other hand, chemoradiotherapy may also be applicable in cases in which surgery is inoperable owing to complications or distant lymph node metastasis. However, chemoradiotherapy using X-ray irradiation can cause late toxicities, including those to the heart. Proton beam therapy is widely used to treat esophageal cancer because of its characteristics, and some comparisons between proton beam therapy and X-ray therapy or surgery have recently been reported. This review discusses the role of proton beam therapy in esophageal cancer in comparison to X-ray therapy and surgery.