Abstract: 978 unique references were identified via the search strategy. All but 50 were excluded by title and abstract screening. Three RCTs met the inclusion criteria; for one small RCT, data were insufficient for inclusion in the meta-analysis. The two RCTs included in the analysis randomly assigned 1945 women, reported HRs for survival adjusted for prognostic factors and based on 1851 women and had an overall low risk of bias, as they satisfied four of the assessment criteria. The third study had an overall unclear risk of bias, as information provided was not adequate concerning random sequence generation, allocation concealment, blinding, or completeness of outcome reporting. Results of the meta-analysis remained unchanged from the previous versions of this review and indicated no differences in overall and recurrence-free survival between women who underwent lymphadenectomy and those who did not undergo lymphadenectomy (pooled hazard ratio (HR) 1.07, 95% confidence interval (CI) 0.81 to 1.43; HR 1.23, 95% CI 0.96 to 1.58 for overall and recurrence-free survival, respectively) (1851 participants, two studies; moderate-quality evidence). We found no difference in risk of direct surgical morbidity between women who underwent lymphadenectomy and those who did not undergo lymphadenectomy. However, women who underwent lymphadenectomy had a significantly higher risk of surgery-related systemic morbidity and lymphoedema/lymphocyst formation than those who did not undergo lymphadenectomy (RR 3.72, 95% CI 1.04 to 13.27; RR 8.39, 95% CI 4.06 to 17.33 for risk of surgery-related systemic morbidity and lymphoedema/lymphocyst formation, respectively) (1922 participants, two studies; high-quality evidence). This review found no evidence that lymphadenectomy decreases risk of death or disease recurrence compared with no lymphadenectomy in women with presumed stage I disease. Evidence on serious adverse events suggests that women who undergo lymphadenectomy are more likely to experience surgery-related systemic morbidity or lymphoedema/lymphocyst formation. Currently, no RCT evidence shows the impact of lymphadenectomy in women with higher-stage disease and in those at high risk of disease recurrence.

Plain-language summary: We found only three trials that compared lymphadenectomy with no lymphadenectomy among women with endometrial cancer. One of these trials could not be included in the meta-analysis of this review, as it provided insufficient information about outcomes for women. When we combined findings from the two remaining trials, which included 1945 women, we found no evidence that women who received lymphadenectomy were less likely to die or have a relapse of their cancer. In addition, severe adverse events experienced as a consequence of lymphadenectomy outnumbered those reported when no lymphadenectomy was performed. The overall quality of the evidence for lymphadenectomy versus standard surgery was moderate for survival outcomes and adverse events (other than evidence for presence or absence of lymphoedema or lymphocyst, which was of high quality). The quality of evidence for quality of life was very low, as this outcome was not reported. The uncertainty of whether lymphadenectomy or no lymphadenectomy is best in the management of early-stage endometrial cancer probably reflects the fact that evidence shows no reduction in death or in disease relapse when lymphadenectomy is performed, rather than lack of evidence. In addition, women undergoing lymphadenectomy experienced more severe adverse events than those who did not undergo lymphadenectomy.