Venous thromboembolism in epithelial ovarian cancer. A prospective cohort study.

Objective: To determine the incidence of symptomatic and incidental venous thromboembolism (VTE) at time of diagnosis and throughout the first year, in patients with suspected epithelial ovarian cancer (EOC).

Methods: Patients were recruited consecutively in the gynecological outpatient clinic at Aalborg University Hospital, Denmark from December 2014 to May 2017. All patients underwent a whole leg compression ultrasound scan (CUS), Computed Tomography (CT) of the thorax in arterial phase at time of inclusion, to be able to diagnose deep vein thrombosis (DVT) and pulmonary embolism (PE), respectively. Patients were followed and systematically screened for VTE throughout 12 months.

Results: Ninety-seven patients with suspected EOC were enrolled in the study and followed up. Within the group of EOC patients (N = 53) eleven were diagnosed with VTE during the first year from EOC diagnosis, the incidence of VTE at time of diagnosis was low (2/53-3.8%). No patients with borderline or benign ovarian neoplasms were diagnosed with VTE. One EOC patient had a VTE during the postoperative period and further eight EOC patients were diagnosed with VTE within the first year, during periods undergoing non-surgical cancer treatment. Median time to VTE was 87 days.

Conclusions: The one year cumulative incidence of VTE in EOC patients was 20.8% with a low incidence at time of diagnosis. A substantial number of VTE cases (73%) appeared during periods of non-surgical oncologic treatment. Future research should focus on risk factors and timing of VTE in EOC patients, as this could have important implications for future prophylaxis guidelines.