Neoadjuvant rectal (NAR) score: Value evaluating the efficacy of neoadjuvant therapy and prognostic significance after surgery?

IntroductionThe Neoadjuvant rectal (NAR) score is a new surrogate endpoint to be used in clinical trials for early determination of treatment response different preoperative therapies. The aim further validate the NAR-score, primarily developed using chemoradiotherapy (CRT) with delay surgery 6–8 weeks, and explore its value other schedules.Materials MethodsThe study included all 9978 patients diagnosed non-metastasized RC 2007–2015 that had undergone was registered Swedish Colorectal Cancer Registry. interest either short-course radiotherapy (scRT)/CRT + delayed surgery, long-course (RT) (C)RT additional chemotherapy, primary or scRT immediate surgery. scRT/CRT groups were divided based on time surgery.ResultsMean NAR-score differed significantly (p < 0.0001) between treatments. chemotherapy lowest mean 16.3 CRT 17.7. There significant difference 0.05) overall survival (OS) recurrence (TTR) Low (<8) compared those High (>16) both CRT- scRT, stronger correlation CRT-patients. C-index model (0.623) not superior when only pathological T- N-stage (0.646).ConclusionsThe prognostic, but it better than pT- pN-stage. However, can still discriminate two treatments have cell killing effect may as an easier method N-stage.