Supplementary Material for: Recurrent and metastatic small cell carcinoma of the esophagus in which long-term survival was achieved by abscopal effect of radiotherapy-A case report

Abstract
Background：Small cell carcinoma of the esophagus (SCCE) is an uncommon tumor characterized by frequent recurrence, metastasis and dismal prognosis. Due to its rare nature, optimal treatment is extremely scarce and randomized studies are not available and are unlikely to be conducted. It has been recognized that high-dose fractionated radiotherapy combined with immunotherapy can induce abscopal effect, which is termed and observed as an immune response leading to an anti-tumoral effect also distant from the irradiated area in patients undergoing radiotherapy, finally will shed new light on the treatment of this rare tumor.
Case Presentation：We report a male patient with small cell carcinoma of the esophagus who, unfortunately, had seen repeatedly recurrence during the first two years after the surgery and salvage treatment were performed, with early detection and effective treatment, especially after the SBRT combined immunotherapy and an abscopal effect taken place, we recorded the patient eventually achieved a long-term survival of 61 months and still alive now with few complications.
Results：Abscopal effect plays a crucial role in the long PFS of this SCCE case. We hypothesized that SBRT combined immunotherapy finally triggered the abscopal effect.