Risk of venous thromboembolism for ovarian cancer patients during first-line therapy after implementation of an Enhanced Recovery After Surgery (ERAS) protocol

Objective: To determine incidence and risk factors for VTE for patients with advanced epithelial ovarian cancer undergoing first-line therapy, including cytoreductive surgery, on an Enhanced Recovery After Surgery (ERAS) protocol. Methods: Medical records were reviewed for patients with FIGO stage IIIA-IVB epithelial ovarian, fallopian tube, or primary peritoneal cancer undergoing primary or interval cytoreductive surgery from March 2017 through September 2019. All patients were enrolled on an ERAS protocol, including 28-day postoperative VTE prophylaxis. Demographic information, medical history, perioperative characteristics, and ERAS compliance were evaluated using univariate and multivariate models. Results: Of 230 patients undergoing cytoreductive surgery via laparotomy, 155 received neoadjuvant chemotherapy and 75 received primary cytoreduction. 38 patients had a VTE during the study period. 13 events (5.7%) were identified at time of diagnosis, 6 (3.9%) during neoadjuvant chemotherapy, 5 (2.2%) within 30 days after surgery, 5 (2.2%) between 30 days and 6 months after surgery, and 9 (3.9%) after the 6-month window. The cumulative incidence of VTE was 6.1% (95% CI, 4.3–8.8%) within 6 months after diagnosis and 8.5% (6.2–11.4%) within 1 year after diagnosis. Estimated blood loss (adjusted HR 1.22 [95% CI, 1.09–1.36], p = 0.001) and history of VTE (7.06 [2.34–21.29], p = 0.001) were independently associated with VTE. Conclusion: With implementation of an ERAS protocol, only 1 in 46 patients experienced a VTE within 30 days after surgery. However, overall VTE occurred in 1 in 16 patients during first-line therapy. Strategies to further reduce VTE risk, especially during neoadjuvant chemotherapy and surveillance, should be investigated.