Lung V20 as a Prognostic Factor of Survival In Patients with Esophageal Cancer Who Received Neoadjuvant Chemoradiotherapy

Abstract

Purpose/Objective(s): Lung and cardiac toxicity were found to be negative prognostic factors of survival in patients with lung or breast cancer who received radiotherapy as part of their treatment. Their roles in patients with operable esophageal carcinoma (EC) who received neoadjuvant chemoradiotherapy are not well established. The purpose of this study was to determine the impacts of lung and / or heart dose on survival outcome in patients with EC receiving trimodality therapy. Materials/Methods: The medical charts and treatment plans of 127 patients with EC treated with trimodality therapy in two institutions between January 2010 and December 2015 were reviewed. Clinical factors and dosimetry parameters were collected to analyze their impacts on survival outcome by using the Kaplan-Meier method and Cox proportional hazards model. Results: Of all the patients, with a majority of clinical stage III disease (n Z 96, 75.6%), squamous cell histology (n Z 121, 95.3%), and smoking history (n Z 120/127, 94.5%), 91 patients (71.7%) underwent pre-treatment feeding jejunostomy. The median dose of radiotherapy was 5,000 cGy (range: 4,000-6,600 cGy). At a median follow-up of 27.7 months (range: 4.7-92.8 months), the median survival of all the patients was 32.7 months (95% confidence interval [CI], 24.9-40.5 months). In the Cox proportional hazards model, pathological complete response (PCR); (hazard ratio [HR], 0.232; 95% CI, 0.127-0.422; p < 0.001), the Eastern Cooperative Oncology Group (ECOG) performance status (HR, 2.111; 95% CI, 1.297-3.437; p Z 0.003), and volume of lung receiving at least 20 Gy (V20); (HR, 1.089; 95% CI, 1.045-1.134; p < 0.001) significantly predicted mortality risk, but not heart mean dose (HR, 1.000; p Z 0.844]. Patients with PCR and lung V20 & 20% had a longer median survival time than those without PCR and with lung V20 >20% (67.5 and 65.7 months vs 24.6 and 27.7 months, respectively; p < 0.001 and < 0.001, respectively). Conclusion: Lung V20 >20% was associated with poor outcomes in patients with EC receiving trimodality therapy. The heart mean dose was not a negative prognostic factor of survival. Limiting the lung radiation dose during radiotherapy in EC patients could potentially improve the outcomes. Future study should aim to reduce the lung dose using novel radiotherapy technique or modalities with a goal of optimizing the outcomes in patients with operable EC.