Irish Journal of Medical Science, 2026 (SCI-Expanded, Scopus)
Background: Systemic inflammation plays an important role in ovarian cancer progression and has been associated with adverse outcomes. Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and systemic immune-inflammatory index (SII) are markers that assess systemic inflammation. Aim: To evaluate the association between preoperative systemic inflammatory markers and the selection of neoadjuvant chemotherapy (NACT), and to assess their prognostic impact on overall survival (OS) and progression-free survival (PFS) in patients with advanced-stage serous epithelial ovarian cancer. Methods: This retrospective cohort study included patients with FIGO stage III–IV high-grade serous epithelial ovarian cancer. Patients underwent either primary debulking surgery (PDS) followed by platinum-based chemotherapy or NACT followed by interval debulking surgery. Preoperative inflammatory markers (NLR, PLR, and SII) were calculated and dichotomized using median cut-off values (NLR ≥ 4.30, PLR ≥ 222, SII ≥ 1350). Results: A total of 239 patients were included; 108 (45.1%) underwent PDS and 131 (54.9%) received NACT. Patients selected for NACT had significantly higher preoperative NLR, PLR, and SII values. In multivariable analyses, high NLR (OR 3.31) and high SII (OR 1.84) were independently associated with increased likelihood of NACT selection, whereas PLR was not. In multivariable analysis, none of the elevated inflammatory markers remained independently associated with prognosis. NACT was associated with inferior OS and PFS after multivariable adjustment. Kaplan–Meier analyses showed that inflammatory markers stratified survival in the PDS group but not in the NACT group. Conclusion: Preoperative systemic inflammatory markers, particularly NLR and SII, are strongly associated with the selection of neoadjuvant chemotherapy in advanced-stage serous epithelial ovarian cancer but do not independently predict survival outcomes.