Table 1_Neutrophil-to-lymphocyte ratio and endometriosis: systematic review and meta-analysis.docx

Background Several biomarkers have been studied to explore the possibility of a non-invasive diagnosis of endometriosis. The aim of this review is to explore the possible role of the neutrophil-to-lymphocyte ratio (NLR) as a biomarker in the diagnosis of endometriosis. Methods A systematic review and meta-analysis was conducted across major databases, including full-text papers in English published from 2008 to 2025. The Population, Intervention, Control, and Outcome (PICO) design approach has been used. Pooled sensibility, specificity, and positive and negative likelihood ratio were applied. A summary receiver operating characteristic curve was also plotted. The bias associated with each included study was evaluated according to the Observational Study Quality Evaluation (OSQE) method. This study is registered on PROSPERO number CRD420251004107. Results The systematic review included seventeen retrospective studies. A total of 6,679 women were studied, of whom 3,980 had endometriosis, whereas 2,699 were in the control group (including both ovarian benign lesions and ovarian cancer). The meta-analysis conducted has shown that NLR has a sensitivity of 0.66 (0.53–0.78) and a specificity of 0.63 (0.52–0.73); in addition, it has a positive likelihood ratio of 1.79 (1.48–2.17) and a negative likelihood ratio of 0.53 (0.41–0.69). Conclusion There are contrasting results about the non-invasive role of both CA 125 and NLR in diagnosing endometriosis. However, studies that investigated the combination of the markers showed promising results.