Survival Analysis Using Neoadjuvant Rectal Score in Locally Advanced Rectal Cancer Patients Who Underwent Surgery After Neoadjuvant Chemoradiotherapy: An Ambispective Study

Purpose The purpose of this study is to stratify patients into various risk groups based on their neoadjuvant rectal (NAR) score and study the predictive value of the NAR score in terms of oncological outcomes. This, in turn, can be used as a surrogate marker to prognosticate the patients and also to study the efficacy of various neoadjuvant therapeutic options. Methodology This ambispective observational study of patients who underwent long-course neoadjuvant chemoradiotherapy (NACTRT), followed by curative surgery in the form of anterior resection (AR) or abdominoperineal resection (APR), from 2010 to 2015 at a high-volume tertiary cancer center in South Kerala, with the survival data collected prospectively. The clinicopathological details of the patients were obtained. ypTNM status was recorded, and the NAR score was calculated. The patients were prospectively followed up for recurrence or death. All endpoints were calculated from the date of the start of NACTRT. Results Four hundred fifty-nine patients were included in the study, with 190 (41.4%) being women and 202 (44%) being less than 60 years old. Two hundred fourteen (46.62%) had lesions of 5-10 cm from the anal verge. Three hundred fifty-nine (78.21%) patients had T3 disease pre-NACTRT. Two hundred twenty-eight patients (51.85%) had undergone APR, and 369 (80.4%) had open surgery. Fifty-one patients (11.1%) had attained pathological complete response (PCR). One hundred twenty-eight patients (27.8%) had disease recurrence, of which 71 had distant metastasis. NAR was a significant predictor of overall survival (OS), disease-free survival (DFS), distant metastasis-free interval (DMFI), and locoregional relapse-free interval (LRFI). On the multivariate analysis of factors predicting survival, only NAR was found to be significant. Conclusion The NAR score is a significant predictor of OS, DFS, LRFI, and DMFI and can be used as a short-term surrogate for survival data in anticipated trials.