Is Total Neoadjuvant Therapy the Solution to the Lateral Pelvic Lymph Nodes in Rectal Cancer? Retrospective Analysis...

Selective lateral pelvic lymph node dissection (LPLND) after chemoradiotherapy for persistent nodes is a standard approach for rectal cancer patients with persistently enlarged lateral pelvic nodes (LPLN). The widely adopted Ogura criteria for LPLND selection were based on long-course chemoradiotherapy (LCRT) outcomes. With the rapid adoption of total neoadjuvant therapy (TNT), the relevance of these criteria in the TNT setting remains uncertain. This study aimed to evaluate the role of TNT in managing LPLNs and to identify risk factors for pathologically positive LPLNs (pLPLNs).

This study retrospectively analyzed patients with locally advanced rectal cancer who underwent LPLND between January 2014 and July 2024. Patients with LPLNs larger than 7 mm at presentation and persistent nodes larger than 4 mm after neoadjuvant therapy underwent LPLND. Risk factors for pLPLN were assesed using multivariable analysis. Local recurrence-free survival (LRFS), disease-free survival (DFS), and overall survival (OS) were estimated using the Kaplan-Meier method.

Among 228 patients who underwent LPLND, 57 (25 %) had pLPLNs. The internal iliac region was the most common site (47 %). Total neoadjuvant therapy was administered to 118 patients (52 %), with 30 (25.4 %) showing pLPLN after TNT. The significant predictors of pLPLN were cT4b stage (odds ratio [OR], 2.60; 95 % confidence interval [CI], 1.31-5.33; p = 0.007) and multiple enlarged LPLN stations (OR, 3.82; 95 % CI, 1.36-10.98; p = 0.011). Total neoadjuvant therapy was not significantly associated with pLPLN (OR, 2.98; 95 % CI, 0.40-21.88; p = 0.284). The 3-year LRFS was similar between the TNT (90 %) and LCRT (85 %) groups (hazard ratio [HR], 1.31; 95 % CI, 0.56-3.08; p = 0.527).

The LCRT- and TNT-treated patients had similar rates of positive lateral nodes. Therefore, the selection criteria for choosing patients for LPLND does not need to change based on the neoadjvuant approach used.