Comparison of Pathologic Complete Response Rates and Oncologic Outcomes in Patients With Surgically Resectable Esophageal Cancer Treated With Neoadjuvant Chemoradiation to 50.4 Gy vs 41.4 Gy.

Background Excellent outcomes and high rates of pathologic complete response (pCR) have been reported in patients with operable esophageal carcinoma using 41.4 Gy of radiation with concurrent carboplatin and paclitaxel. With pCR rates similar to studies using higher doses, it remains unclear whether doses greater than 41.4 Gy result in improved outcomes. This study aims to compare pCR rates and oncologic outcomes in patients treated with neoadjuvant chemoradiation to 50.4 Gy vs 41.4 Gy. Methods We reviewed the charts of patients with operable esophageal carcinoma who were treated with neoadjuvant chemoradiation followed by oncologic resection. Our primary endpoint was the pCR rate. Secondary endpoints were overall survival, progression-free survival (PFS), and toxicity.  Results We identified 43 patients meeting inclusion criteria. Nineteen patients were treated with 41.4 Gy and 24 were treated with 50.4 Gy. Cohorts were well-matched, except for a significantly higher percentage of patients with adenocarcinoma (AC) (89.5% vs 54.2%, p = 0.02), usage of intensity-modulated radiation therapy (IMRT) (100% vs 47.6%; p = 0.002), and usage of carboplatin, plus paclitaxel (100% vs 75%; p = 0.003) in the 41.4 Gy group. The pCR rate for the cohort was 44.2%. No differences in the pCR rate (41.7% vs 47.4%), three-year overall survival (OS) (73.7% vs 77.5%), or three-year PFS (52.8% vs 43.7%) were observed. Late toxicity rates also did not vary significantly (p = 0.2). No grade 4 or 5 events were observed. Conclusion In this small series, there were no differences in the pCR rate, PFS, or OS between those treated with 50.4 Gy and 41.4 Gy. Larger, multi-institutional series are needed to validate these findings.