Factors Predictive of Tumor Recurrence and Survival After Initial Complete Response of Esophageal Squamous Cell Carcinoma to Definitive Chemoradiotherapy

Purpose: To assess factors predictive of recurrent disease and survival after achieving initial complete response (CR) to chemoradiotherapy (CRT) for esophageal cancer. Methods and Materials: Patients who had clinical Stage I-IVA esophageal cancer and received definitive CRT between 2001 and 2007 were retrospectively analyzed. Results: Of 269 patients with esophageal cancer, 110 who achieved CR after definitive CRT were included in the analyses. Chemoradiotherapy mainly consisted of 2 cycles of cisplatin and fluorouracil with concurrent radiotherapy of 60 Gy in 30 fractions. We identified 28 recurrences and 28 deaths during follow-up. The cumulative 1- and 3-year recurrence rates were 18% and 32%, respectively. By univariate and multivariate analyses, tumor category (hazard ratio [HR] 6.6; 95% confidence interval [CI] 1.4-30.2; p = 0.015) was an independent risk factor for local recurrence, whereas age (HR 3.9; 95% CI 1.1-14.0; p = 0.034) and primary tumor location (HR 4.5; 95% CI 1.6-12.4; p = 0.004) were independent risk factors for regional lymph node or distant recurrences. The cumulative overall 1- and 3-year survival rates were 91% and 66%, respectively. As expected, recurrence was associated with poor survival (p = 0.019). By univariate and multivariate analyses, primary tumor location (HR 3.8; 95% CI 1.2-12.0; p = 0.024) and interval to recurrence (HR 4.3; 95% CI 1.3-14.4; p = 0.018) were independent factors predictive of survival after recurrence. Conclusion: Risk of recurrence after definitive CRT for esophageal cancer was associated with tumor category, age, and primary tumor location; this information may help in improved prognostication for these patients.