Incidence of recurrent venous thromboembolism and bleeding complications in patients with cancer and isolated distal deep vein thrombosis

Background: Isolated distal deep vein thrombosis (IDDVT) is a common clinical presentation of DVT. The efficacy and safety of anticoagulant therapy for the management of IDDVT in patients with cancer are unclear. We sought to assess the incidence of recurrent venous thromboembolism (VTE) and major bleeding in this patient population.Methods: A systematic search of MEDLINE, EMBASE and PubMed, from inception to June 2, 2022 was performed. The primary efficacy outcome was recurrent VTE and the primary safety outcome was major bleeding. The secondary outcomes were clinically relevant non-major bleeding (CRNMB) and mortality. The incidence rates of thrombotic, bleeding, and mortality outcomes were pooled using random effects model and expressed as events per 100 patient-months with associated 95 % confidence intervals (CI).Results: Out of a total of 5234 articles, 10 observational studies including 8160 patients with cancer and IDDVT were included in the analysis. The incidence rate of recurrent VTE was 5.65 (95 % CI: 2.09-15.30) per 100 patient-years regardless of type and duration of anticoagulant therapy. The incidence rate of major bleeding was 4.08 (95 % CI: 2.52-6.61) per 100 patient-years. The incidence rates for CRNMB and mortality per 100 patient -years were 8.11 (95 % CI: 5.56-11.83) and 30.22 (95 % CI: 22.60-40.42.89), respectively.Conclusion: Patients with cancer and IDDVT are at high risk of developing recurrent VTE and bleeding compli-cations (both major bleeding and CRNMB). More studies are needed to define the optimal management for this high-risk population.