The prognostic role of lateral pelvic lymph nodes in patients with low and mid rectal cancer

Purpose Lateral pelvic lymph nodes (LPLNs) represent a potential route of locoregional dissemination in locally advanced rectal cancer (LARC). LPLN management remains controversial, with routine LPLN dissection advocated in some Eastern centres, whereas Western strategies rely primarily on neoadjuvant treatment followed by total mesorectal excision (TME) without systematic lateral pelvic lymph node dissection (LPLND). As a result, the prognostic significance of magnetic resonance imaging (MRI)-suspected LPLNs in patients treated with contemporary neoadjuvant approaches remains uncertain, particularly in Western cohorts where pathological confirmation is rare. This study aimed to determine the incidence of MRI-suspected LPLN involvement and to evaluate its prognostic impact on overall survival (OS) and disease-free survival (DFS). Methods This was a retrospective study at the Institut Jules Bordet that included patients treated for LARC between January 1, 2007 and December 31, 2021. Pre-treatment MRI was used to identify suspected LPLN involvement. The prognostic impact of MRI-suspected LPLNs on OS and DFS was assessed. Results A total of 115 patients with LARC were included. Twenty-one patients (18.3%) had MRI-suspected LPLNs at diagnosis. Despite a higher risk of LPLN recurrence in the group with MRI-suspected LPLN (9.5% vs 1.1%), no statistically significant association was observed between pre-treatment LPLN status and OS or DFS (P = 0.88 and P = 0.73, respectively). Conclusion In this cohort, MRI-suspected LPLN involvement was not associated with impaired survival outcomes. Prospective studies using standardised radiological criteria and treatment strategies are warranted to better define the prognostic role of LPLNs in LARC.