Prognostic value of lymphocyte to monocyte ratio for metastatic renal cell carcinoma: a systematic review and meta-analysis

To systematically evaluate the prognostic value of lymphocyte-to-monocyte ratio (LMR) for the prognosis of patients with metastatic renal cell carcinoma (mRCC). This systematic review and meta-analysis followed the PRISMA 2020 guidelines and was registered in PROSPERO (CRD420251246337). Relevant literature up to November 2025 was systematically searched in PubMed, Embase, Web of Science, and Cochrane Library. Observational studies assessing the relationship between LMR and overall survival (OS) and progression-free survival (PFS) in mRCC patients were included. Two researchers independently screened the literature, extracted data, and assessed the quality using the Newcastle-Ottawa Health Scale (NOS). Pooled hazard ratios (HR) and their 95% confidence intervals (CIs) were calculated using a random-effects model. Heterogeneity was assessed using the I² statistic, and sensitivity analysis and Egger’s test were performed to assess publication bias. A total of 11 studies involving 1763 patients with mRCC were included. Meta-analysis results showed that lower LMR was significantly associated with shorter OS (HR = 1.64, 95% CI: 1.30–2.07, P < 0.0001) and shorter PFS (HR = 1.33, 95% CI: 1.14–1.56, P = 0.0003). OS analysis showed high heterogeneity (I² = 82%), with sensitivity analysis suggesting the Barua 2019 study was the primary source; while PFS heterogeneity was low (I² = 15%). Egger’s test indicated publication bias in OS ( P = 0.04), but the association remained significant after trimming and complement correction (corrected HR = 1.44, 95% CI: 1.10–1.89), indicating robust results. LMR is significantly associated with OS and PFS in patients with mRCC, and low LMR indicates poor prognosis. Although OS is heterogeneous, the results are robust. As an economical and readily available inflammatory marker, LMR can help with risk stratification and individualized treatment decisions in mRCC, but its standardization of threshold values and its role in assessing prognosis still require further validation through prospective studies.