Gao XP, et al. - Whether pretreatment lymphocyte-to-monocyte ratio (LMR) has value as a prognosticator in ovarian cancer (OC) patients, was investigated by analyzing evidence from relevant retrospective cohort studies in this meta-analysis. These studies were identified from electronic databases, including PubMed and Embase, from inception through October 2018. Pooled HRs and their 95% CIs for overall survival (OS) and progression-free survival (PFS) were estimated by using a random-effects model. The reference group comprised low LMR group. Researchers analyzed 12 studies, including 3,346 OC cases at baseline. A favorable prognosis was observed in relation to a higher pretreatment LMR level. In stratified analyses, younger patients (<55 years) vs older patients (≥55 years) experienced a greater protective effect of LMR on survival. This finding was corroborated in meta-regression analysis.