Prognostic factors in patients after definitive chemoradiation using involved‐field radiotherapy for esophageal cancer in a phase II study

BACKGROUND A prospective study was performed on the use of chemoradiotherapy (CRT) for esophageal cancer (EC) with involved-field radiation therapy (IFRT), based on 18-fluorodeoxyglucose positron-emission tomography. Prognostic factors for overall survival (OS) were analyzed. METHODS Eligible patients included 63 adults with newly diagnosed, untreated, inoperable stage I-IV EC with lymph node metastases. Patients received 80 mg/m2 nedaplatin per day on day 1, 800 mg/m2 5-fluorouracil on days 1-4 intravenously repeated every 28 days for two to four cycles, and combined IFRT. Irradiation was applied only to the primary tumor and positive lymph nodes. RESULTS Three-year progression-free survival and OS rates were 44.9% and 47.5%, respectively. The median survival time was 31.5 months. In univariate analyses for OS, Karnofsy Performance Scale <90% (P = 0.027), initial stage (P = 0.0087), T stage (P = 0.066), N stage (P = 0.000086), M stage of M1 (P = 0.0042), dysphagia score (P = 0.00017), tumor marker squamous cell carcinoma antigen >1.5 ng/mL (P = 0.0054), gross tumor volume (GTV) > 60 cc (P = 0.00011), and relative dose intensity (RDI) of chemotherapy ≤50% (P = 0.063) were found to be associated with significantly or marginally worse OS. In multivariate analyses for OS, GTV ≥ 60 cc (P = 0.00040), RDI < 50% (P = 0.00034), and cN2-3 (P = 0.0020) were associated with significantly worse OS. CONCLUSION GTV, RDI and N grading, were associated with OS after definitive CRT using IFRT for EC.