Prevention of Venous Thromboembolism in Patients with Ovarian Cancer: The State of the Research.

Ovarian cancer (OC) remains one of the most lethal gynaecological malignancies worldwide, largely due to the absence of effective screening strategies, which frequently results in diagnosis at advanced stages of disease, together with the development of chemoresistance. Moreover, clinical outcomes are significantly compromised by cancer-associated thrombosis (CAT), particularly venous thromboembolism (VTE), which is a major cause of morbidity and mortality in this population. Despite the well-established association between OC and VTE, evidence on thromboprophylaxis remains fragmented. This comprehensive narrative review focuses on the prevention of VTE in OC patients, examining the epidemiology, risk factors, underlying pathophysiological mechanisms, emerging biomarkers, current thromboprophylaxis strategies and further clinical implications. The available evidence indicates a consistently high incidence of VTE across all disease stages, with particularly elevated risk during chemotherapy and among specific histological subtypes, notably clear cell tumours. Established clinical risk factors are supported by consistent evidence across studies, while coagulation abnormalities appear to reflect tumour aggressiveness, highlighting the close interplay between thrombosis and OC biology. Among the biomarkers investigated, D-dimer is the most consistently validated marker for VTE prediction and diagnosis, whereas the clinical utility of emerging biomarkers and currently available risk assessment models, including the Khorana score, remains limited by inconsistent performance and insufficient external validation. Although thromboprophylaxis may offer benefit in selected high-risk groups, uncertainties remain regarding optimal patient selection, timing, and therapeutic approaches. The predominance of retrospective, single-centre studies and heterogeneous patient cohorts further constrains the current evidence base. Future research should prioritise large, prospective, multicentre investigations, the development and external validation of OC-specific risk prediction models, and well-designed clinical trials evaluating personalised thromboprophylaxis strategies to reduce the burden of VTE and improve clinical outcomes in OC patients.