224PD Predictors for recurrence after initial clinical complete response to definitive chemoradiotherapy in esophageal squamous cell carcinoma patients

Abstract

Background Definitive chemoradiotherapy(dCRT) is a curative treatment option for esophageal cancer and could be an alternative to esophagectomy. However, due to lack of effective diagnostic methods for the response evaluation, some patients who actually harbor residual disease after dCRT were falsely diagnosed as clinical complete response(cCR)andeventuallyexhibitrelapse.Thepurposeofthisstudywasto investigate the pattern, timing and risk factors for recurrence after cCR in esophageal squamous cell carcinoma(ESCC) patients after dCRT. Methods Patients who had clinical Stage I-IIIESCC and achieved cCR after dCRT between 2001 and 2015 were retrospectively analyzed. Factors associated with recurrence were analyzed using univariate and multivariate analyses. Local recurrence(LR) included the primary tumor while regional and distant recurrence was defined as non-local recurrence(non-LR). Results Therewere 128 cCRpatients withthe mean age of60.2(range: 36~83). Aftera meanfollow-upof42months,weidentified71(55.5%) recurrences(44LRand27non- LR). LRs occurred significantly earlier then non-LRs.(Mean: 233 days versus 467 days, p = 0.012). Morethan 90% LRwere detected within 2 years compared with 3 years for non-LR. Bymultivariateanalyses,patientage<60(hazardratio[HR]:2.799;95% confidence interval[CI]:1.277~6.136; p = 0.01) and pretreatment clinical N3 stage(HR:4.404; 95%CI:1.197~16.206; p = 0.026) were independent predictors for LR while no predictors were identified for non-LR. Conclusions More than 50% of patients who achieved cCR after dCRT developed disease recurrence. Variables related to LR were: patient age<60 and pretreatment clinical N3 stage. Patients with high risk LR should be strictly followed with panendoscopy for the first two years to allow timely salvage treatment before disease progression renders them inoperable. Legal entity responsible for the study N/A Funding Chang Gung Memorial Hospital, Linkou Disclosure All authors have declared no conflicts of interest.