Validation of neoadjuvant rectal cancer(NAR) score as a surrogate endpoint for disease free survival in Chinese FOWARC study.

Abstract

e15162 Background: NAR score is considered as a surrogate endpoint for survival in patients with locally advanced rectal cancer who received neoadjuvant treatment. Here we validate it in Chinese FOWARC study, especially in the chemotherapy alone arm. Methods: NAR score is calculated based on cT, ypT, ypN as reported for patients who received surgery in FOWARC study. NAR score is correlated to DFS with COX regression and Kaplan-Meier analysis. Results: 451 patients had surgery, 147 in FU-RT group, 152 in FOLFOX-RT arm and 152 in FOLFOX arm. NAR score is a significant prognostic factor in COX regression (P=0.000, HR 1.034, 95% CI 1.024-1.045) and in FOLFOX alone group (p=0.001, HR 1.030, 95% CI 1.013-1.047). When NAR score is quartile to <5, 5-10, 10-15,>15, the survival of patients is listed below, and similar to pathological staging. Conclusions: NAR score can be used as a surrogate endpoint for disease free survival Chinese patients. But it is not superior to pathological stage, especially in patients who received chemotherapy alone. [Table: see text]