Beyond prophylaxis: Extended risk of venous thromboembolism following primary debulking surgery for ovarian cancer

Objective: To determine the incidence and risk factors for venous thromboembolism (VTE) within six months after primary debulking surgery (PDS) for epithelial ovarian cancer (EOC). Methods: In a historical cohort, we estimated the cumulative incidence of clinically diagnosed VTE within 6 months among consecutive women who underwent PDS for EOC at a single institution from 1/1/2003 to 12/31/2011. We evaluated perioperative variables as potential risk factors of VTE within 6 months during the postoperative period using univariate and multivariable Cox proportional hazards models. Results: Among 860 women without an immediate history (past 30 days) of a VTE, the cumulative incidence of VTE was 7.5% (95% CI, 5.7–9.3) by 30 days and 13.8% (95% CI, 11.4–16.2) by 6 months following surgery. Macroscopic residual disease (adjusted HR 1.99 [95% CI 1.35–2.94] vs microscopic), increasing estimated blood loss (1.25 [1.05–1.49] per doubling), longer hospital length of stay (3.00 [1.57–5.75]), and experiencing a cardiac event within 30 postoperative days (2.72 [1.55–4.80]) were independently associated with subsequent VTE within 6 months. In-hospital VTE prophylaxis included heterogeneous approaches; dual prophylaxis did not impact 30-day or 6-month VTE rates. Conclusions: VTE occurred in 1 in 7 women with EOC within 6 months of PDS—a substantial risk of VTE that extends into the adjuvant chemotherapy period. Novel prophylactic measures should be explored in these women at high risk for VTE.