Lateral lymph node dissection reduces local recurrence of locally advanced lower rectal cancer in the absence of preoperative neoadjuvant chemoradiotherapy: A systematic review and meta-analysis
Background: The role of lateral lymph node dissection (LLND) in the treatment of locally advanced lower rectal cancer remains controversial. The present study was conducted to compare total mesorectal excision (TME) with or without LLND in clinical stage II/III lower rectal cancer.Methods: Studies published in PubMed, Embase, Ovid, Cochrane Library, Google Scholar and the ClinicalTrials.gov databases were systematically searched for studies that compared TME with or without LLND in clinical
... LND in clinical stage II/III lower rectal cancer. Subgroup analysis was performed based on whether preoperative neoadjuvant chemoradiotherapy (nCRT) was undertaken. The hazard ratios (HR), relative risk (RR) and weighted mean difference (WMD) were pooled.Results: Twelve studies that included 4458 patients were identified in the current meta-analysis. Pooled data demonstrated that TME with LLND was associated with significantly longer operation time (WMD 90.73 min, P<0.001), more intraoperative blood loss (WMD 303.20 mL, P<0.001) and postoperative complications (RR=1.35, P=0.02). Urinary dysfunction (RR 1.44, P=0.38), sexual dysfunction (RR 1.41, P=0.17), and postoperative mortality (RR=1.52, P=0.70) were similar between the two groups. No statistically significant differences were observed in OS (HR 0.93, P=0.62), DFS (HR 0.99, P=0.96), total recurrence (RR 0.98, P=0.83), lateral recurrence (RR 0.49, P=0.14) or distant recurrence (RR 0.95, P=0.78) between the two groups regardless the use of nCRT. LLND significantly reduced local recurrence rate of patients who did not receive nCRT (RR 0.71, P=0.004); while the difference was not significant when nCRT was performed (RR 0.70, P=0.36).Conclusions: Our study found LLND could not significantly improve survival in locally advanced lower rectal cancer, but could reduce the local recurrence in the absence of preoperative nCRT. The advantage of controlling local recurrence might be replaced with nCRT.Registration: The protocol for this meta-analysis was registered prospectively with PROSPERO (CRD42020135575) in 16 May 2019.