Clinical influence of prophylactic lateral lymph node dissection on oncologic outcomes of patients with mid-low rectal cancer undergoing mesorectal excision: a meta-analysis

Abstract

Background: Although several recent meta-analyses have investigated the clinical influence of the addition of lateral lymph node dissection (LLND) on oncologic outcomes in patients with mid-low rectal cancer (RC) undergoing mesorectal excision (ME), most studies included in such meta-analyses were retrospectively designed. Therefore, this study aimed to explore the clinical influence of prophylactic LLND on oncologic outcomes in patients with mid-low RC undergoing ME.

Methods: A comprehensive electronic search of the literature up to July 2022 was performed to identify studies that compared oncologic outcomes between patients with mid-low RC undergoing ME who underwent LLND and patients with mid-low RC undergoing ME who did not undergo LLND. A meta-analysis was performed using fixed-effects models and the generic inverse variance method to calculate hazard ratios (HRs) and 95% CIs, and heterogeneity was analyzed using I² statistics.

Results: A total of 6 studies, consisting of 3 randomized and 3 propensity score matching studies, were included in this meta-analysis. The results of the meta-analysis of 2 randomized studies demonstrated no significant effect of prophylactic LLND on improving oncologic outcomes concerning overall survival (OS) (HR, 1.22; 95% CI, 0.89-1.69; I² = 0%; P = .22) and relapse-free survival (RFS) (HR, 1.03; 95% CI, 0.81-1.31; I² = 28%; P = .83).

Conclusion: The results of this meta-analysis revealed no significant influence of prophylactic LLND on oncologic outcomes-OS and RFS-in patients with mid-low RC who underwent ME.

Keywords: Lateral lymph node dissection; Mesorectal excision; Meta-analysis; Mid-low rectal cancer; Oncologic outcomes.