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.