Venous thromboembolism in ovarian cancer: incidence, risk factors and impact on survival

Objectives: Ovarian cancer has a higher incidence of venous thromboembolism (VTE) than other cancers. Clear cell cancers carry the highest risk at 11-27%. The aim of this study was to identify the predisposing factors for VTE in a population of ovarian cancer patients and to determine the influence of VTE on overall survival.

Study design: VTE events were identified from hospital and general practice/community care records for all patients with ovarian cancer who were diagnosed and treated in a tertiary cancer center between 2006 and 2010.

Results: The overall incidence of VTE was 9.7% (33) in 344 patients. Sixteen (48%) had pulmonary embolism. Six (18%) presented with VTE. Five (15%) had VTE diagnosed during pre-treatment routine CT scanning. Eleven (33%) developed VTE following surgery and eleven (33%) developed VTE during chemotherapy. Risk factors associated with the occurrence of VTE were BMI≥30 (p<0.01), clear cell carcinoma (p<0.05), advanced stage (p<0.01), high grade (p<0.01) and CA125>500 IU/ml (p<0.001). The occurrence of VTE was associated with decreased overall survival time (p<0.001).

Conclusion: The incidence of VTE is high in ovarian cancer especially in the clear cell subtype. VTE adversely affects survival in ovarian cancer. Obesity, high grade and stage of cancer, clear cell subtype and high CA 125 level should be incorporated into protocols of VTE prophylaxis in women with ovarian cancer.