Lymph Node Regression to Neoadjuvant Chemoradiotherapy in Patients with Locally Advanced Rectal Cancer: Prognostic Implication and a Predictive Model

Abstract

AimCurrently, few studies have focused on the prognostic impact of lymph node regression to neoadjuvant chemoradiotherapy (NCRT) in rectal cancer. This study aimed to explore the prognostic impact of lymph node regression grade (LRG) in patients with locally advanced rectal cancer (LARC) following NCRT and radical surgery and develop a predictive nomogram for disease-free survival (DFS). MethodsLARC patients undergoing NCRT and radical surgery between 2013 and 2014 were enrolled and divided into LRG low (≤ 2), middle (3–9), and high (≥ 10) groups. Clinicopathological characteristics and survival outcomes were compared. Predictors for DFS were identified by Cox regression analysis, and a nomogram was constructed. ResultsA total of 257 LARC patients were eligible, including LRG low (n = 149), middle (n = 59), and high (n = 49) groups. Higher LRG score was associated with higher TRG, more advanced ypT and ypN stages, and poorer OS and DFS (all P < 0.001). Cox regression analysis demonstrated that tumor differentiation (poor and anaplastic, HR = 2.048, P = 0.048), ypTNM stage (HR = 2.389, P = 0.015), and LRG-sum (HR = 1.020, P = 0.029) were independent prognostic determinants for DFS after NCRT. A nomogram for DFS was developed with a C-index of 0.68 (95%CI 0.64–0.72). ConclusionLRG is an important prognostic indicator for DFS in LARC patients after NCRT. A predictive nomogram based on LRG was developed to guide more tailored adjuvant treatment and surveillance.