Meta-analysis of randomized controlled trials on primary ambulatory thromboprophylaxis in patients with ovarian cancer receiving chemotherapy.

Ovarian cancer (OC) is highly associated with venous thromboembolism (VTE). The OC cells stimulate thrombin generation, and chemotherapy potentiates the prothrombotic effect of cancer cells by damaging endothelium and enhancing hypercoagulability. Recently, primary ambulatory thromboprophylaxis (PATP) has been studied as a potential treatment in cancer patients undergoing chemotherapy with an aim of reducing the incidence of VTE and potentially prolonging survival. A meta-analysis was performed of randomized controlled trials of PATP vs control in patients with OC receiving chemotherapy. The primary outcome measure was the incidence of VTE. The secondary outcome measure was the incidence of major bleeding complications. Two articles published between 2012 and 2020 fulfilled selection criteria. The incidence of VTE was 0.9% in the PATP group and 1.8% in the control group. However, the pooled risk ratio was not statistically significant at 0.69 (95% CI: 0.08 to 5.67; P  = 0.73). The absolute risk difference was -0.03 (95% CI, -0.17 to 0.11; P  = 0.66). There was no statistically significant reduction in VTE by providing PATP to patients with OC receiving chemotherapy. Routine PATP should not be recommended in ambulatory OC patients. Future randomized trials are necessary to define the high-risk subset of OC patients who may benefit from PATP.