Elective Nodal Irradiation vs. Involved-Field Irradiation for Stage Ⅱ-Ⅳ Cervical Esophageal Squamous Cell Carcinoma Patients Undergoing Definitive Concurrent Chemoradiotherapy: A Retrospective Propensity Study with Eight-Year Survival Outcomes

Abstract

Definitive concurrent chemoradiotherapy (dCCRT) is suggested as the standard treatment for cervical esophageal squamous cell carcinoma (CESCC). This retrospective propensity study compared the eight-year survival outcomes and acute treatment toxicities of these patients treated with elective nodal irradiation (ENI) versus involved-field irradiation (IFI). Patients with stage Ⅱ-Ⅳ CESCC treated with dCCRT in our institution between January 1, 2007 and December 31, 2020 were enrolled in the study. All the patients were restaged according to the American Joint Commission (AJCC) 8th edition criteria. The propensity score matching (PSM) was used to minimize the effects of treatment selection bias and potential confounding factors including sex, age, ECOG score, clinical T stage (cT), clinical N stage (cN), clinical TNM stage (cTNM) and radiation dose between the ENI group and IFI group. Survival and the prognostic factors were evaluated. The 131 eligible patients underwent ENI (60 patients, 45.8%) or IFI (71 patients, 54.2%). The median follow-up time was 95.3 months (range, 28.0-186.2 months) for all the patients. The median OS, 1-, 3-, 5-, and 8-year OS rates were 44.4 months, 87.8%, 55.5%, 39.0%, and 28.3%, respectively. After PSM, there were 49 patients in each group. The median OS, 1-, 3-, 5-, and 8-year OS rates for ENI and IFI group were 32.0 months, 83.7%, 48.9%, 38.8% and 32.4% versus 45.2 months, 89.8%, 52.7%, 38.2%, 26.6%, respectively (P = 0.984; HR 0.99, 95% CI 0.61-1.62). Similar locoregional control was obtained in both groups. The tendency of leukocytopenia and neutropenia was higher in ENI than in IFI (59.2% versus 38.8%; P = 0.068 and 30.6% versus 14.3%; P = 0.089) at the end of dCCRT. Cervical esophageal squamous cell carcinoma patients undergoing definitive concurrent chemoradiotherapy has a satisfactory prognosis with organ conservation. The involved-field irradiation might be a better alternative owing to similar overall survival outcomes and local control with less toxicity of myelosuppression.