Safety and Effectiveness of Direct Oral Anticoagulants for the Treatment of Gastrointestinal Cancer-Associated Venous Thromboembolism.

BACKGROUND: Patients with gastrointestinal cancer (GICA) are at high risk for venous thromboembolism (VTE). Data from randomized clinical trials in cancer-associated VTE suggest that direct oral anticoagulants (DOACs) conferred similar or superior efficacy but a heterogeneous safety profile in patients with GICA. We compared the safety and effectiveness of DOACs in patients with GICA and VTE at MD Anderson Cancer Center. MATERIALS AND METHODS: This was a retrospective chart review of patients with GICA and VTE receiving treatment with DOACs for a minimum of 6 months. Primary outcomes were the proportion of patients experiencing major bleeding (MB), clinically relevant non-major bleeding (CRNMB), and recurrent VTE. Secondary outcomes were time to bleeding and recurrent VTE. RESULTS: A cohort of 433 patients with GICA who were prescribed apixaban (n = 300), or rivaroxaban (n = 133) were included. MB occurred in 3.7% (95% confidence interval [CI] 2.1-5.9), CRNMB in 5.3% (95% CI 3.4-7.9), and recurrent VTE in 7.4% (95% CI 5.1-10.3). The cumulative incidence rates of CRNMB and recurrent VTE were not significantly different when comparing apixaban to rivaroxaban. CONCLUSION: Apixaban and rivaroxaban had a similar risk of recurrent VTE and bleeding and could be considered as anticoagulant options in selected patients with GICA and VTE.

External validation of a novel electronic risk score for cancer-associated thrombosis in a comprehensive cancer center.

Venous thromboembolism (VTE) is a significant complication for cancer patients undergoing systemic therapy. We performed an independent external validation for a recently derived and validated a novel electronic health record (EHR) VTE risk score in a comprehensive cancer center. Adult patients with incident cancer diagnoses were identified from MD Anderson Cancer Center Tumor Registry 1/2017-1/2021. Baseline covariates extracted at the time of first-line systemic therapy included demographics, cancer site/histology, stage, treatment, complete blood count, body mass index, recent prolonged hospitalization, and history of VTE or paralysis. VTE was ascertained using an institution-specific natural language processing radiology algorithm (positive predictive value of 94.8%). The median follow-up for 21 142 cancer patients was 8.1 months. There were 1067 (5.7%) VTE within 6 months after systemic therapy. The distribution of the novel score for 0-, 1, 2, 3, 4, 5+ was 5661, 3558, 3462, 3489, 2918, and 2054; while the corresponding 6-month VTE incidence was 1.3%, 3.1%, 5.4%, 7.3%, 9.3%, and 13.8%, respectively (c statistic 0.71 [95% CI 0.69-0.72] with excellent calibration). In comparison, the Khorana score had a c statistic of 0.64 [95% CI 0.62-0.65]. The two risk scores had 80% concordance; the novel score reclassified 20% of Khorana score (3530 low-to-high with 9.0% VTE; 734 high-to-low with 3.4% VTE) and led to a 25% increment in VTEs captured in the high-risk group. In conclusion, the novel score demonstrated consistent discrimination and calibration across cohorts with heterogenous demographics. It could become a new standard to select high-risk populations for clinical trials and VTE monitoring.