Incidence and timing of venous thromboembolism after surgery for gynecological cancer

Objective: This study aims to determine the incidence, timing, and risk factors of clinical venous thromboembolism. Methods: A cohort of patients who had major gynecologic cancer surgery between 1998 and 2008 was identified. Secondarily, a nested case-control design wherein patients who had clinical VTE within 90 days after surgery were considered cases. Controls were matched on age, race, surgery date, and cancer site. Risk factors were evaluated for VTE within 90 days, and late VTE between 8 and 90 days. Results: We identified 4158 women, 18 years or older, without a history of recent thrombosis. We observed 126 cases of clinical VTE within 90 days of surgery (incidence 4%) of which 96 (76%) occurred after post-operative day 7. In a multivariable model including age, ASA, BMI, race, and site of cancer, only ovarian cancer was a significant predictor for VTE within 90 days (HR 2.8; 95% CI 1.6, 5.0). In the nested case-control study, we identified hospital stay ≥ 5 days (OR 2.8; 95% CI 1.5, 5.1) and prior VTE (OR 2.6; 95% CI 1.1, 6.1) as significant risk factors for VTE within 90 days. Only hospital stay ≥ 5 days (OR 2.5; 95% CI 1.3, 4.7) was significantly associated with late VTE between 8 and 90 days. Conclusion: In gynecologic cancer patients, over 75% of VTE are detected more than 7 days after surgery. Patients with ovarian cancer, prolonged hospitalization, or a history of VTE are at highest risk of developing clinical VTE. Such patients would be optimal candidates for clinical trials evaluating extended VTE prophylaxis.