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

Objectives: Patients with ovarian cancer have been shown to have high rates of venous thromboembolism (VTE), with previous studies reporting an up to 16% overall incidence of symptomatic VTE, and a 7.5% cumulative incidence of VTE within the first 30 days after surgery. The goal of this study is to determine the updated 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 all 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 at a single institution. All patients were enrolled on an ERAS protocol, including 28-day postoperative VTE prophylaxis. Demographic information, past medical history, perioperative characteristics, and ERAS compliance were collected and evaluated using univariate and multivariate Cox proportional hazards models. Download : Download high-res image (86KB) Download : Download full-size image 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. Conclusions: With implementation of an ERAS protocol and 28-day postoperative VTE prophylaxis, only 1 in 46 patients experienced a VTE within 30 days after surgery, a rate markedly lower than historically reported for cytoreductive procedures. However, overall VTE occurred in 1 in 16 patients during first-line therapy. Half of the venous thromboembolic events occurred prior to surgery and 36.8% occurred more than 30 days after surgery. Strategies to further reduce VTE risk, especially during neoadjuvant chemotherapy and surveillance, should be investigated.