Survival outcomes of endometrial cancer patients with disease involving the lower uterine segment: A meta-analysis

•Tumors involvement of the lower uterine segment significantly affects survival outcomes of endometrial cancer patients.•The effect seems to be independent of other known predictors of endometrial cancer survival.•Sensitivity analysis revealed that the possibility of statistical bias was low among included studies. Lower uterine segment (LUS) involvement is encountered in a small proportion of endometrial cancer patients and is associated with aggressive histological features. Despite the available evidence, there seems to be a lack of consensus concerning its actual impact on disease related survival. The search strategy involved the Medline, Scopus, Clinicaltrials.gov, EMBASE, Cochrane Central Register of Controlled Trials CENTRAL and Google Scholar databases. Nine studies were included in the present systematic review that recruited 3300 patients. Pooled hazard ratios (HR) were retrieved from Cox-regression analyses to limit the confounding effect of other factors that influence the course of the disease. Nine articles were included in the present meta-analysis that involved 3300 endometrial cancer patients. The meta-analysis revealed a significant difference in progression free survival that was found increased in patients without LUS involvement (HR 1.59, 95 % CI 1.22, 2.05, data from 9 studies). Similarly, a significantly smaller overall survival was observed among patients with LUS involvement (HR 1.69, 95 % CI, 1.34, 2.13, data from 7 studies). Sensitivity analysis revealed that there were no outliers in either outcome, however, the possibility of data manipulation could not be ruled out entirely. The results of this meta-analysis indicate that lower uterine segment involvement is associated with decreased survival outcomes. It remains unclear if these patients can benefit from adjuvant treatment in the absence of other negative prognostic indicators and this needs to be examined by future studies.