Neoadjuvant rectal score is prognostic for survival: A population-based propensity-matched analysis

Area of Science:

• Oncology
• Clinical Trials
• Cancer Research

Background:

• The Neoadjuvant Rectal (NAR) score is being evaluated as a surrogate endpoint for overall survival (OS) in clinical trials.
• This study validates the NAR score's utility using a large national cancer registry.

Purpose of the Study:

• To assess the Neoadjuvant Rectal (NAR) score as a predictor of overall survival (OS) in patients with locally advanced rectal adenocarcinoma.
• To determine if the NAR score's predictive value is independent of adjuvant chemotherapy (AC) receipt.

Main Methods:

• Utilized the National Cancer Database for patients with clinical stage II/III rectal adenocarcinoma (RAC) undergoing neoadjuvant chemoradiation (CRT) and surgery.
• Categorized patients into low-, intermediate-, and high-NAR score subgroups and analyzed overall survival (OS) using Kaplan-Meier and logistic regression.
• Employed propensity-matched analysis to compare OS outcomes between NAR subgroups, both with and without adjuvant chemotherapy (AC).

Main Results:

• A total of 12,452 patients were analyzed; 15.2% achieved a pathologic complete response.
• Significant differences in 5-year OS were observed across NAR subgroups (p < 0.001), both with (93% vs. 88% vs. 75%) and without (85% vs. 76% vs. 68%) adjuvant chemotherapy.
• Logistic regression confirmed NAR strata as a significant predictor of 5-year OS.

Conclusions:

• The Neoadjuvant Rectal (NAR) score is a robust predictor of 5-year overall survival in locally advanced rectal cancer.
• The NAR score's predictive capability for overall survival is maintained regardless of adjuvant chemotherapy administration.
• The NAR score serves as a valuable neoadjuvant response measure for clinical trial endpoints in heterogeneous rectal cancer populations.