Effect of radiotherapy target areas in the prognosis of esophageal cancer in the era of immunotherapy

Esophageal cancer is one of the most common malignancies. This study aimed to explore the influence of related factors such as immunotherapy, altitude level, radiotherapy target volume, and radiotherapy dose on the prognosis of patients with locally advanced and advanced esophageal cancer in the plateau region. We retrospectively collected data related to all patients with locally advanced and advanced esophageal cancer who completed definitive radiotherapy at Yunnan Cancer Hospital from January 2017 to January 2023. A total of 274 patients were included, with a median follow-up time of 54.8 months. The median OS and PFS were 15.0 months and 11.0 months, respectively. Immunotherapy significantly improved patient survival, especially for patients receiving immunotherapy after radiotherapy. Adjuvant therapy (including chemotherapy, immunotherapy, targeted therapy, P = 0.004) and GTV (P = 0.015) were independent predictors of OS, while body mass index (BMI, P = 0.037) was independent predictors of PFS. Patients with smaller target areas of PTV, CTV, GTV, GTVnd, and NEW had a better prognosis. The prognosis of recent efficacy is better than that of ineffective. Patients with disease progression within 3 months after radiotherapy have a worse prognosis. The altitude of the residence and the radiotherapy dose had no noticeable effect on the prognosis of patients with esophageal cancer. The lesion location, GTV, and simultaneous integrated boost (SIB) radiotherapy affected the occurrence of esophageal fistula.