Retroperitoneal Lymph Node Dissection in Colorectal Cancer with Lymph Node Metastasis: A Systematic Review

SIMPLE SUMMARY: Retroperitoneal lymph node metastasis (RPLNM) occurs in up to 6% of colorectal cancer (CRC) patients. In general, there is no consensus on the treatment paradigm or optimal management of retroperitoneal lymph node dissection (RPLND) in CRC patients, necessitating a systematic review of the literature to evaluate preoperative imaging modalities, perioperative chemotherapy and radiotherapy regimens, and oncological outcomes of RPLND in CRC. Nineteen studies of 541 patients were included. Based on this systematic review and analysis, RPLND is a feasible treatment option with limited morbidity and possible oncological benefit for both synchronous and metachronous RPLNM in CRC. Future prospective clinical trials are required in order to establish further evidence for RPLND in the context of RPLNM in CRC. ABSTRACT: The benefits and prognosis of RPLND in CRC have not yet been fully established. This systematic review aimed to evaluate the outcomes for CRC patients with RPLNM undergoing RPLND. A literature search of MEDLINE, EMBASE, EMCare, and CINAHL identified studies from between January 1990 and June 2022 that reported data on clinical outcomes for patients who underwent RPLND for RPLNM in CRC. The following primary outcome measures were derived: postoperative morbidity, disease free-survival (DFS), overall survival (OS), and re-recurrence. Nineteen studies with a total of 541 patients were included. Three hundred and sixty-three patients (67.1%) had synchronous RPLNM and 178 patients (32.9%) had metachronous RPLNM. Perioperative chemotherapy was administered in 496 (91.7%) patients. The median DFS was 8.6–38.0 months and 5-year DFS was 24.4% (10.0–60.5%). The median OS was 25.0–83.0 months and 5-year OS was 47.0% (15.0–87.5%). RPLND is a feasible treatment option with limited morbidity and possible oncological benefit for both synchronous and metachronous RPLNM in CRC. Further prospective clinical trials are required to establish a better evidence base for RPLND in the context of RPLNM in CRC and to understand the timing of RPLND in a multimodality pathway in order to optimise treatment outcomes for this group of patients.