Cancer-Associated Venous Thromboembolism Among Solid and Hematological Malignancies: A Comprehensive National Study

Introduction: Venous thromboembolism (VTE) is a leading cause of non-cancer-related mortality in patients with active cancer. The pathophysiology of cancer-associated thrombosis (CAT) involves a complex interplay of factors including hypercoagulability, endothelial injury, and stasis, often exacerbated by cancer therapies. Despite advancements in understanding CAT, there remains a critical need to identify changes in epidemiological patterns and assess the impact of demographic factors such as gender, race, and cancer subtype, especially with the advent of novel antineoplastic therapies. This study aims to provide a comprehensive analysis of VTE incidence in a large cohort of cancer patients, investigating its association with cancer subtype (solid versus hematological), gender, and race.

Methods: We utilized the National Inpatient Sample (NIS) Database to identify patients admitted with active cancer from 2016 to 2018. Baseline demographics and comorbidities, including cancer type, were collected using ICD-10 codes. Exclusion criteria included patients younger than 18, those with missing data, prior history of thromboembolism, history of hypercoagulable diseases, cancer of unknown origin, and those with both solid and hematological malignancies. Patients were stratified into two cohorts: those with solid malignancies and those with hematological malignancies. Greedy propensity matching using R was performed to match the two cohorts in a 1:1 ratio based on age, gender, race, use of antiplatelets and anticoagulants, and active treatment with chemotherapy, immunotherapy, and radiation. Univariate analysis pre- and post-match, along with binary logistic regression analysis post-match, were used to evaluate the incidence of VTE. A p-value of <0.05 was considered statistically significant.

Results: Out of 1,233,832 cancer patients, 63,505 (5.1%) were diagnosed with acute VTE. Female patients had a significantly higher incidence of VTE compared to males (5.5% vs. 4.8%; p<0.001). Significant racial disparities in VTE incidence were observed, with black patients having the highest incidence (6.4%), followed by whites (5%), Native Americans and Hispanics (4.9%), and Asians (3.9%). Regarding cancer subtype, 78.6% (n=970,405) had solid malignancies and 21.4% (n=263,427) had hematological malignancies. Patients with solid malignancies exhibited a significantly higher incidence of VTE compared to those with hematological malignancies (5.4% vs. 4.1%; p<0.001). Among solid tumors, gastrointestinal and lung malignancies were the most prevalent, contributing to 28.7% and 25.9% of VTE cases, respectively. Among hematological malignancies, non-Hodgkin lymphoma was the most significant contributor, accounting for 42% of VTE cases. Post-matching analysis via binary logistic regression confirmed the initial findings, showing a significantly higher VTE rate in patients with solid malignancies compared to those with hematological malignancies (5.4% vs. 4.1%; p<0.001).

Conclusion: This study underscores the considerable burden of VTE in cancer patients, with notable variations based on gender, race, and cancer subtype. The higher VTE incidence in females and racial disparities suggest a need for personalized risk assessment and prevention strategies. Solid malignancies, particularly gastrointestinal and lung cancers, pose a greater VTE risk compared to hematological malignancies, indicating that these patients might benefit from more aggressive prophylactic measures. These findings advocate for targeted VTE prophylaxis strategies tailored to high-risk cancer populations, which could lead to improved patient outcomes and reduced morbidity and mortality related to cancer-associated venous thromboembolism.