Incidence of venous thromboembolism in patients with advanced stage ovarian cancer undergoing neoadjuvant chemotherapy: Is it time for thromboprophylaxis?

Objectives: Our objectives were to determine the incidence, timing, and risk factors for venous thromboembolisms (VTEs) in patients with advanced stage epithelial ovarian cancer (EOC) who received neoadjuvant chemotherapy (NACT). We explored the utilization of direct-acting oral anticoagulants (DOACs) for VTE treatment. Methods: This retrospective cohort study included patients with advanced stage EOC receiving NACT followed by interval cytoreductive surgery (ICS) at a single institution. Risk factors were compared between patients with versus without VTE between EOC diagnosis and 180 days after ICS. Bleeding complications were compared between patient who received a DOAC versus non-DOAC. Results: VTE cases occurred amongst 33 of the 154 (21.4%) patients with 4 (2.6%) concurrent with EOC diagnosis, 9 (5.8%) between EOC diagnosis and NACT start, 13 (8.4%) between NACT start and ICS, and 7 (4.5%) within 180 days after ICS. There were no statistically significant differences in risk factors assessed (age, body mass index, functional status, histology, Khorana score, and smoking history) between patients with versus without VTE. Eleven patients (33.3%) received a DOAC for VTE treatment. There were no significant differences in number of intraoperative blood transfusions (p = 0.38), blood loss (p = 0.95), or bleeding complications (p = 0.53) between patients treated with a DOAC versus a non-DOAC. Conclusion: There is a high incidence of VTE events (21.4%) in patients with advanced stage EOC undergoing NACT. Two-thirds of the VTEs may have been prevented with thromboprophylaxis as they occurred between EOC diagnosis and ICS. These data support consideration of thromboprophylaxis in all patients with advanced stage EOC undergoing NACT.