Background: To identify the incidence of newly occurring venous thromboembolism (VTE) in patients with ovarian cancer receiving neoadjuvant chemotherapy (NACT). Methods: Using our prospectively maintained ovarian cancer database, we identified all ovarian cancer patients who received NACT at our institution from 4/15-9/18. VTE events included clinically diagnosed deep venous thrombosis (DVT) or pulmonary embolism (PE). Patients who presented with VTE prior to induction of NACT or patients on anticoagulation therapy prior to diagnosis were excluded. The incidence of newly occurring thrombotic events were categorized according to treatment phases, defined as 1) NACT prior to interval debulking surgery (IDS); 2) intraoperative and 30-day post-IDS; and 3) adjuvant chemotherapy. Results: 290 patients underwent NACT during the study period. Thirty-eight patients (13%) who presented with VTE, 12 (4%) on anticoagulation at presentation, and 4 (1.4%) seeking only a second opinion were excluded from analysis. Of the 236 evaluable patients, the overall rate of VTE during all treatment phases was 15% (35/236). In treatment phase I, 11% (27/236) of patients experienced VTE during NACT. In phase II, an additional 2.5% (6/236) developed VTE in the intraoperative and 30-day postoperative period. In phase III, an additional 0.8% (2/236) experienced a thrombotic event >30 days postoperatively. Sevety-seven percent (27/35) of VTE events occured during phase I. Conclusions: Patients receiving NACT for advanced ovarian cancer are at high risk for the development of clinically detectable thromboembolic events. The highest rate of new VTE events was seen during induction of NACT, a phase of treatment traditionally without any prophylactic anticoagulation. Further research regarding the timing of thromboprophylaxis for this patient population is warranted.

Data are expressed as n (%) unless otherwise specified NACT neo-adjuvant chemotherapy VUSvariant of uncertain significance