Conditional survival probability in patients with resected oesophageal adenocarcinoma receiving neoadjuvant chemotherapy

Abstract

Background: Traditional recurrence and survival figures are based upon factors determined at baseline and become less relevant for patients over time. Conditional survival (CS) estimates future prognosis based upon survival to a specific time point since treatment. We analysed CS and conditional recurrence-free survival (CRFS) data for patients in the United Kingdom undergoing surgery and neoadjuvant chemotherapy for gastro-oesophageal junction (GOJ) or oesophageal adenocarcinoma (OAC). Methods: 378 patients with GOJ/OAC treated with neoadjuvant chemotherapy and surgical resection from 2003-2012 were identified. Clinicopathological and survival data was collected as part of the Oesophageal Cancer Clinical and Molecular Stratification (OCCAMS) consortium. A multivariable parametric survival model was used to analyse factors associated with overall survival and recurrence from time of surgery. Results: The cohort includes 305 males (80.7%) with median age 65 (range 28-83) years. 5-year RFS conditional on recurrence-free years to date increased over time (see table). For those with stage T3/4, moderately-poorly differentiated tumours with lymphovascular invasion, 5-year disease-specific survival (DSS) improved from 7.7% for those with node-positive, R1 disease to 45.4% conditional on 3 years post-treatment survival; compared with 55.6% actuarial 5-year DSS increasing to 86.7% conditional on 3 years post-treatment survival for patients with N0 R0 disease. Age, sex, year of surgery, and Siewert classification had no association with recurrence or mortality rate. Conclusions: CRFS and CS provide a more dynamic estimation of future recurrence risk and survival among patients who have accrued survival time, especially in patients with high-risk features, including positive resection margins. Margin and node positivity govern early relapse events but as the time from surgery increases these factors become less relevant. (Table Presented).