Direct oral anticoagulant-associated bleeding complications in patients with gastrointestinal cancer and venous thromboembolism

Background: Direct oral anticoagulants (DOACs) have become widely used for cancer-associated venous thromboembolism (VTE). However, DOAC-associated bleeding complications remain challenging, especially in patients with gastrointestinal (GI) cancer. This study aimed to compare the bleeding outcomes between patients with upper or lower GI cancers and those without GI cancer. Methods: Using the COMMAND VTE Registry-2 database, which is a multicenter registry enrolling 5197 consecutive acute symptomatic VTE patients among 31 centers in Japan between January 2015 and August 2020, we identified 1149 active cancer patients with DOACs (upper GI cancer: N = 88; lower GI cancer: N = 114; non-GI cancer: N = 947). The primary outcome was major bleeding during anticoagulation therapy, which was evaluated in the competing risk regression model. Results: The upper GI cancer group had a lower mean body weight, and most often had anemia. The cumulative 5-year incidence of major bleeding was higher in the upper GI cancer group (upper GI cancer: 22.4 %, lower GI cancer: 15.4 %, and non-GI cancer: 11.6 %, P = 0.015). The most frequent major bleeding site in the upper GI cancer group was the upper GI (53 %), followed by the lower GI (24 %). After adjusting for the confounders, the excess risk in upper GI cancer relative to non-GI cancer remained significant for major bleeding (adjusted subhazard ratio, 2.25; 95 %CI, 1.31-3.87, P = 0.003), but that in lower GI cancer was insignificant. Conclusions: Upper GI cancer, but not lower GI cancer, as compared to non-GI cancer was associated with a higher risk for major bleeding during anticoagulation therapy with DOACs. Clinical Trial Registration: URL: http://www.umin.ac.jp/ctr/index.htm Unique identifier: UMIN000044816.