A Novel Score Using Lymphocyte-to-Monocyte Ratio in Blood and Malignant Body Fluid for Predicting Prognosis of Patients with Advanced Ovarian Cancer

SIMPLE SUMMARY: In recent decades, research efforts have enabled an increased awareness of critical roles of systemic inflammatory markers in malignant body fluids of ovarian cancer patients. The aim of this study was to investigate the prognostic value of the lymphocyte-to-monocyte ratio (LMR) in malignant body fluid (malignant pleural effusion or malignant ascites) (mLMR) and the combination of LMR in peripheral blood (bLMR) and mLMR for predicting the prognosis of patients with advanced-stage epithelial ovarian cancer. The results highlighted that both low bLMR (p = 0.013) and low mLMR (p = 0.006) were associated with poor prognosis of ovarian cancer. Furthermore, combined scoring of these two factors (p < 0.001) was found to be a better factor for predicting disease recurrence of ovarian cancer. ABSTRACT: (1) Background: The lymphocyte-to-monocyte ratio (LMR), one of the systemic inflammatory markers, has been shown to be associated with prognosis of various solid tumors. However, no study has reported clinical utility of the LMR of malignant body fluid (mLMR) (2) Methods: We retrospectively analyzed clinical data of the final 92 patients of a total of 197 patients with advanced ovarian cancer newly diagnosed from November 2015 and December 2021 using our institute big data. (3) Results: Patients were divided into three groups according to their combined bLMR and mLMR scores (bmLMR score): 2, both bLMR and mLMR were elevated; 1, bLMR or mLMR was elevated; and 0, neither bLMR nor mLMR was elevated. A multivariable analysis confirmed that the histologic grade (p = 0.001), status of residual disease (p < 0.001), and bmLMR score (p < 0.001) were independent predictors of disease progression. A low combined value of bLMR and mLMR was strongly associated with a poor prognosis in patients with ovarian cancer. (4) Conclusions: Although further studies are required to apply our results clinically, this is the first study to validate the clinical value of mLMR for predicting prognosis of patients with advanced ovarian cancer.