Cancer Management and Research (Feb 2019)
Pretreatment lymphocyte-to-monocyte ratio as a predictor of survival among patients with ovarian cancer: a meta-analysis
Abstract
Xu-ping Gao,1,* Yan-hua Liu,2,* Ze-ying Liu,1 Li-jun Wang,3 Chun-xia Jing,1 Sui Zhu,4 Fang-fang Zeng1 1Department of Epidemiology, School of Medicine, Jinan University, Guangzhou 510632, Guangdong, China; 2Department of Nutrition, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China; 3Department of Nutrition, School of Medicine, Jinan University, Guangzhou 510632, Guangdong, China; 4Department of Medical Statistics, School of Medicine, Jinan University, Guangzhou 510632, Guangdong, China *These authors contributed equally to this work Introduction: In this meta-analysis, we analyzed retrospective cohort studies that assessed the prognostic potential of the pretreatment lymphocyte-to-monocyte ratio (LMR) among patients with ovarian cancer (OC).Materials and methods: We comprehensively searched electronic databases, including PubMed and Embase, from inception through October 2018. A random-effects model was used to calculate pooled HRs and their 95% CIs for overall survival (OS) and progression-free survival (PFS). The low LMR group was treated as the reference group.Results: Twelve studies, including 3,346 OC cases at baseline, were included. Overall, our results indicated that LMR was positively associated with both OS (HR: 1.85, 95% CI: 1.50–2.28, P<0.001; I2=76.5%) and PFS (HR: 1.70, 95% CI: 1.49–1.94, P<0.001; I2=24.4%) among OC patients. Stratified analyses indicated that, for OS, the LMR’s protective effect was more evident in studies conducted among younger patients (<55 years) than in those conducted among older patients (≥55 years; P for interaction =0.017), which was confirmed by meta-regressionanalysis (P=0.004). Conclusion: This study suggested that a higher pretreatment LMR level was associated with a favorable prognosis among OC patients. Future large-scale prospective clinical trials are needed to confirm the prognostic value of LMR among OC patients. Keywords: ovarian cancer, lymphocyte-to-monocyte ratio, prognosis, meta-analysis