Lateral lymph node dissection: a routine procedure for rectal cancer?—a narrative review

Abstract

Background and Objective: Rectal adenocarcinomas located below the peritoneal reflection occasionally metastasize to lateral pelvic lymph nodes (LPLNs) that are outside the standard surgical boundaries. LPLN metastasis is associated with increased local recurrence and poorer survival outcomes. Managing rectal cancer with LPLN involvement remains complex and challenging. This narrative review evaluates the current optimal strategies for LPLN management. Methods: A comprehensive search of relevant studies was performed across major electronic databases, including PubMed, Ovid, MEDLINE, and Google Scholar, to identify English-language articles published up to September 21, 2024. Search terms included combinations of keywords such as “lateral pelvic lymph node”, “rectal cancer”, and “lateral lymph node dissection”. Key Content and Findings: The effectiveness of neoadjuvant chemoradiotherapy (nCRT) in eradicating metastatic LPLNs remains debated. LPLN removal may be unnecessary in patients with clinically negative LPLNs after nCRT. However, selective lateral lymph node dissection (LLND) is recommended for patients with persistent clinically positive LPLNs. The role of LLND in patients responding well to nCRT remains controversial. The emergence of total neoadjuvant therapy (TNT) has further complicated the debate over the significance of LLND. In case without neoadjuvant therapy, high-quality magnetic resonance imaging (MRI) evaluation is essential, and it is extremely crucial to perform LLND in patients with enlarged LPLNs, even in case of T1 or T2 rectal cancer. Although the cutoff value for determining enlarged LLND remains the greatest problem, a Japanese randomized control trial recommended combining total mesorectal excision (TME) with LLND for stage III low rectal cancer to improve local control. Patients with clinical stage III disease who underwent TME with LLND had higher recurrence-free survival (RFS) rate compared to those who underwent TME alone [hazard ratio (HR) 1.49, 95% confidence interval (CI): 1.02–2.17]. However, the evidence supporting an overall survival benefit is limited. In contrast, it might be possible to omit LLND in patients with stage II rectal cancer. Conclusions: Although LLND is unlikely to improve prognosis, it may have the potential for improving local control. Optimal individual indications for LLND should be considered based on accurate preoperative diagnosis and the use or type of preoperative treatment.