The Efficacy And Safety Of Lateral Lymph Node Dissection For Patients With Rectal Cancer:A Systematic Review And Meta-analysis

Objective: To evaluate the efficacy and safety of lateral lymph node dissection(LLND)for the patients with rectal cancer by performing a meta-analysis of published clinical control studies using evidence-based medicine.So as to provide help for clinician’s diagnosis and treatment decision.Methods: To collect clinical studies for the comparison of LLND and non-LLND in patients with rectal cancer,PubMed,Embase,The Cochrane Library,Web of Science,China National Knowledge Infrastructure(CNKI),Wan Fang Data and China Biology Medicine(CBM)were searched from inception to August,2019,and the language was limited to English.All the domestic and foreign clinical control studies on rectal cancer radical resection with and without LLND were collected,the required data were extracted,and meta-analysis was performed using STATA 15.0 software.For continuous variables,such as surgical duration(SD)and intraoperative blood loss(BL),weighted mean differences(WMD)and95% confidence intervals(CI)were used for statistical description.For dichotomous variable,such as postoperative recurrence(PR),postoperative complications(PC),odds ratios(OR)and 95% CI were used for statistical analysis.5-year overall survival(5-OS)and 5-year disease-free survival(5-DFS)were described by hazard ratio(HR)and 95%CI to evaluate the efficacy and safety of LND in patients with rectal cancer.Results: Twenty-six studies met the inclusion criteria,of which 5 were Randomized Controlled Trials(RCTs)and 21 were cohort study,including 6,865 patients with rectal cancer(3171 in the LLND group and 3694 in the non-LLND group).In terms of efficacy,meta-analysis results showed that there was no significant difference in the 5-year overall survival(HR=1.23,95%CI =0.84-1.80,P=0.288),5-year disease-free survival rate(HR=1.07,95%CI =0.85-1.36,P=0.559),local recurrence rate(OR=0.64,95%CI =0.39-1.05,P=0.077)and distant metastasis rate(OR=1.59,95%CI =0.38-6.63,P=0.526)between LLND group and non-LLND group.Concerning safety,the incidence of urinary dysfunction(OR=2.32,95%CI=1.27-4.24,P=0.006)and male sexual dysfunction(OR=5.17,95% CI=1.33-20.16,P=0.018)was significantly increased in the LLND group.In addition,the surgical duration of LLND group was significantly prolonged(WMD=107.20,95%CI =101.59-112.81,P< 0.001),and the intraoperative blood loss was significantly increased(WMD=254.46,95%CI=221.54-287.38,P< 0.001).However,there was no statistically significant difference between the two groups in perioperative complications(OR=1.44,95%CI =1.00-2.07,P=0.051)and perioperative mortality(OR=3.00,95%CI =0.12-73.89,P=0.502).Conclusion: Lateral lymph node dissection would prolong the surgical duration,increase the intraoperative blood loss and was related to increased postoperative urinary dysfunction and male sexual dysfunction.However,the differences in the increase of perioperative complications and mortality,the improvement of long-term survival rate and the long-term prognosis were not statistically significant,requiring further verification by a larger sample size and higher quality clinical study.