Targeting Monocytes and Their Derivatives in Ovarian Cancer: Opportunities for Innovation in Prognosis and Therapy

Ovarian cancer remains the most lethal gynaecological malignancy primarily due to late-stage diagnosis, high recurrence rate, and limited treatment efficacy. Current diagnostic tools, including imaging and serum markers, lack sufficient sensitivity and specificity for early detection. Increasing evidence highlights the critical role of myeloid-derived immune cells within the tumour microenvironment in shaping ovarian cancer progression and therapy response. Monocytes and their derivatives are central regulators of immune suppression, chemoresistance, and metastatic dissemination in ovarian tumours. Their recruitment and polarisation are governed by several signalling pathways offering promising therapeutic targets. Strategies including monocyte depletion, TAM reprogramming, MDSC maturation, DC vaccines, and their synergistic use with chemotherapy or immune checkpoint inhibitors are being explored to restore anti-tumour immunity in ovarian cancer. Parallel to therapeutic potential, the lymphocyte-to-monocyte ratio and its reciprocal monocyte-to-lymphocyte ratio have also emerged as potential accessible and cost-effective prognostic tools that predict disease aggressiveness and survival in ovarian cancer. This review features the diagnostic, prognostic, and therapeutic significance of monocytes and their derivatives in ovarian cancer management and highlighting new opportunities for next-generation immunomodulatory therapies.