Integrating Downstaging in the Risk Assessment of Patients With Locally Advanced Rectal Cancer Treated With Neoadjuvant Chemoradiotherapy: Validation of Valentini's Nomograms and the Neoadjuvant Rectal Score

Background: Adjuvant chemotherapy is controversial in patients with locally advanced rectal cancer after preoperative chemoradiation. Valentini et al developed 3 nomograms (VN) to predict outcomes in these patients. The neoadjuvant rectal score (NAR) was developed after VN to predict survival. We aimed to validate these tools in a retrospective cohort at an academic institution. Patients and Methods: VN and the NAR were applied to 158 consecutive patients with locally advanced rectal cancer treated with chemoradiation followed by surgery. According to the score, they were divided into low, intermediate, or high risk of relapse or death. For statistical analysis, we performed Kaplan-Meier curves, log-rank tests, and Cox regression analysis. Results: Five-year overall survival was 83%, 77%, and 67% for low-, intermediate-, and high-risk groups, respectively (P = .023), according to VN, and 84%, 71%, and 59% for low-, intermediate-, and high-risk groups, respectively (P = .004), according to NAR. When the score was considered as a continuous variable, a significant association with the risk of death was observed (NAR: hazard ratio, 1.04; P < .001; VN: hazard ratio, 1.10; P < .001). Conclusion: We confirmed the value of these scores to stratify patients according to their individual risk when designing new trials.