Who is a candidate at the initial presentation? Prediction of positive lateral lymph node and survival after dissection.

Abstract

Metastatic lateral pelvic lymph node (LPN) in rectal cancer has a significant clinical impact on the prognosis and treatment strategies. But there are still debates regarding prediction of lateral pelvic lymph node metastasis and its oncological impact. This review explores the evidence for predicting lateral pelvic lymph node metastasis and survival in locally advanced rectal cancer. Until now many studies have reported that magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) are considered as essential tools for predicting metastatic LPN, with MRI-based size criteria, particularly the short-axis diameter of LPN. But several studies have reported that the addition of tumor location or artificial intelligence (AI) can further enhance diagnostic accuracy. Western practices focus more on neoadjuvant chemoradiation (nCRT), while Eastern countries focus more on lateral pelvic lymph node dissection (LPND). LPND has been shown to reduce lateral local recurrence (LLR) rates compared to total mesorectal excision (TME) alone, particularly in patients with enlarged LPNs, but its impact on overall survival is uncertain. The decision to perform LPND should be individualized according to LPN size and response to nCRT; and through selective LPND based on those criteria, patients could achieve a balance between the benefit of local control and the risk of surgical complications from LPND, such as sexual and urinary dysfunction.