Management, treatment and prognostic significance of lateral lymph node metastases in rectal cancer\u2014a regional cohort study

E Agger,M L Lydrup,F Jörgren,P Buchwald,V Åkerlund,O Ekberg

doi:10.1007/s00384-021-04018-1

Abstract

PurposeLateral lymph node metastases in rectal cancer remain a clinical challenge. Different treatment regimens have been suggested. This retrospective regional cohort study examines outcome after combined oncological and surgical treatment of MRI-positive lateral lymph nodes (LLN).MethodsData from the Swedish Colorectal Cancer Registry (SCRCR) and patient records were used for retrospective analysis of resected high-risk rectal cancers between 2009 and 2014. The aim was to compare tumour characteristics, neoadjuvant therapy, recurrence and outcome after lateral lymph node dissection.ResultsOne thousand and one hundred nineteen cases were identified and after exclusion 344 patients with cT3–T4 ≤ 10 cm from the anal verge were analysed. Thirty (8.7%) patients with MRI-positive LLN were identified. Synchronous distant metastases were associated with MRI-positive LLN (p-value 0.019). Long-course chemoradiotherapy was clinical practice in cases of MRI-positive LLN. No differences in local (p-value 0.154) or distant (p-value 0.343) recurrence rates between MRI-positive LLN patients and MRI-negative patients were detected. Only four patients underwent lateral lymph node dissection (LLND). There was no significant difference in overall survival during follow-up between the MRI-negative (CI at 95%; 99–109 months) and MRI-positive group (CI at 95%; 69–108 months; p-value 0.14).ConclusionLateral lymph node metastases present a challenging clinical situation. The present study shows that combination of neoadjuvant therapy and selective LLND is an applicable strategy in cases of MRI-positive LLN.

Highlights

Lateral lymph node (LLN) stations are located outside the normal reign of standard total mesorectal excision (TME) in rectal cancer surgery
Tumours located in the lower two-thirds of the rectum, advanced T-stage and histopathological risk factors are associated with increased risk of lateral lymph node metastases (LLNM) [2]
Management of suspected LLNM in rectal cancer surgery is a challenging clinical situation. In this regional cohort study, we examine a treatment strategy reliant on CRT and lateral lymph node dissection (LLND) only in selected patients

Summary

Introduction

Lateral lymph node (LLN) stations are located outside the normal reign of standard total mesorectal excision (TME) in rectal cancer surgery. Lymph node metastases outside the mesorectum might be located along the iliac vessels in the pelvis, in the inguinal fossa and in paraaortic lymph node stations. Metastases along the iliac vessels are considered. N2-disease whereas tumour growth in the inguinal or paraaortic lymph nodes is considered M1 disease [1]. Tumours located in the lower two-thirds of the rectum, advanced T-stage and histopathological risk factors are associated with increased risk of lateral lymph node metastases (LLNM) [2]. LLNM are associated with an increased risk of local recurrence (LR) and decreased survival [2]. Pelvic MRI is the most accurate method to identify LLNM before and after neoadjuvant therapy [3]

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