Pretreatment lymphocytopenia is an adverse prognostic biomarker in advanced‐stage ovarian cancer

The aim of this study was to investigate the prognostic significance of lymphocytopenia in advanced‐stage ovarian cancer. We retrospectively reviewed 506 patients with advanced‐stage ovarian cancer at Yonsei Cancer Hospital. This study included two cohorts of patients: a neoadjuvant chemotherapy (NAC) group (N = 247) and a primary debulking surgery (PDS) group (N = 259). The absolute lymphocyte count was recorded before treatment. A receiver operating characteristic (ROC) curve analysis was used to determine the cutoff for defining lymphocytopenia in the NAC cohort and followed by multivariate analysis. Subsequently, lymphocytopenia was assessed in the PDS cohort by multivariate analysis. A further analysis was performed to evaluate the absolute lymphocyte count as a continuous variable. An absolute lymphocyte count of 1.49 × 109/L was determined as the cutoff for the ROC curve analysis in the NAC cohort, and the multivariate analysis revealed that lymphocytopenia was an independent prognostic factor for poor progression‐free survival (PFS) [hazard ratio (HR), 1.50; 95% confidence interval (CI), 1.07‐2.11] and overall survival (OS) (HR, 2.02; 95% CI, 1.21‐3.40). In the PDS cohort, the multivariate analysis showed that lymphocytopenia was an independent prognostic factor for poor PFS (HR, 1.73; 95% CI, 1.20‐2.49) and OS (HR, 1.87; 95% CI, 1.27‐2.75). The absolute lymphocyte count was a significant factor when analyzed as a continuous variable in both the NAC and PDS cohorts. Pretreatment lymphocytopenia is an independent adverse prognostic factor in patients with advanced‐stage ovarian cancer.