Thrombosis in ovarian cancer: a case control study

Background: Thrombotic events are common in cancer patients and have been associated with an adverse prognosis in large registry-based studies. Methods: A retrospective cohort of 417 patients with ovarian cancer treated at a tertiary cancer centre between 2006 and 2009 was studied to identify the incidence and risk factors for thrombotic events and the prognostic impact of thrombosis. Patient outcomes were evaluated against a matched control group without thrombosis. Results: Ninety-nine thrombotic events occurred in 90 patients (21.6%) from 8 months before diagnosis to 56 months following diagnosis, peaking in the 4 months following diagnosis. Patients with thrombosis were older (mean 65 vs 61 years, P = 0.007), had a worse performance status (PS >= 2: 29.9% vs 9.5%, P<0.0001) and had a more advanced FIGO stage (FIGO III/IV 75.6% vs 56.9%, P<0.0001) than patients without thrombosis. Shorter overall survival was seen in patients with pulmonary embolism and pelvic/lower limb deep vein thrombosis than without thrombosis (P = 0.001). When the control group was matched for stage and PS, no survival difference was seen (P = 0.91). Conclusion: Ovarian cancer patients with thrombotic events had a shorter survival. However, when matched for prognostic factors (PS and FIGO stage), thrombosis did not impact upon prognosis.