TREATMENT OUTCOME AND RECURSIVE PARTITIONING ANALYSIS-BASED PROGNOSTIC FACTORS IN PATIENTS WITH ESOPHAGEAL SQUAMOUS CELL CARCINOMA RECEIVING PREOPERATIVE CHEMORADIOTHERAPY

Purpose To analyze the clinical outcomes and devise a prognostic model for patients with operable esophageal carcinoma who underwent preoperative chemoradiotherapy (CRT). Methods and Materials A total of 269 patients were enrolled into three clinical trials assessing preoperative CRT at our institution. We assessed the significance of the pretreatment and treatment factors with regard to tumor recurrence and long-term survival and used recursive partitioning analysis to create a decision tree. Results At a median follow-up of 31 months for the surviving patients, the median overall survival of all 180 patients in this study was 31.8 months, and the 5-year overall survival rate was 33.9%. The median event-free survival was 24.1 months, and the 5-year event-free survival rate was 29.3%. Of the 180 patients, 129 (71.7%) also underwent esophagectomy, and the perioperative mortality rate was 7.8%. A pathologic complete response was achieved by 58 patients (45%). The 5-year overall survival rate was 57.1% for patients who attained a pathologic complete response and 22.4% for those with gross residual disease ( p = 0.0008). Recursive partitioning analysis showed that female patients who achieved a clinical response and underwent esophagectomy had the most favorable prognosis ( p p = 0.0002). Conclusion Although preoperative CRT was generally effective and well-tolerated, an individualized approach is necessary to improve outcomes. Strategies to increase the response and reduce treatment failure should be investigated.