The Application of Current Proposed Venous Thromboembolism Risk Assessment Model for Ambulatory Patients With Cancer

Abstract

Venous thromboembolism (VTE) is a commonly encountered problem in patients with cancer. In recent years, cancer treatment paradigm has shifted with most therapy offered in ambulatory outpatient settings. Excess of half VTEs in patients with cancer occur in outpatient settings without prior hospitalization, where current practice guidelines do not recommend routine prophylaxis. Risk assessment models (RAMs) for VTE in such patients were recently introduced. This study aims to assess the practical application of one of these models in clinical practice. Medical records and hospital electronic database were searched for patients with cancer having VTE. Known risk factors were collected, and risk assessment was done using the Khorana RAM. Over a 10-year period, 346 patients developed VTE in ambulatory settings. Median age was 57 and 59.0% were females. Lower extremities were involved in 196 (56.6%), while 96 (27.7%) had pulmonary embolism. Most (76.6%) patients had stage IV disease, only 9.0% had stage I or II disease. Only 156 (45.1%) patients were on active chemotherapy, for whom Khorana risk assessment score was calculated. In these patients, high risk was identified in 31 (19.9%) patients, while 81 (51.9%) had intermediate risk and 44 (28.2%) had low risk. No patients were on prophylaxis prior to VTE. Most ambulatory patients with cancer who developed VTE were not on chemotherapy, and many of those who were on active treatment had low Khorana risk scores. This illustrates the need to modify the model or develop a new one that takes into consideration this group of patients.

Platelet-Cancer Interplay: Molecular Mechanisms and New Therapeutic Avenues

“…Thromboembolic disease is the second leading cause of death in cancer patients diagnosed with obesity, leukocytosis, anemia or thrombocytosis. Thrombocytosis is associated with poor survival and increased risk of tumor metastasis and venous thromboembolism (VTE) in a wide variety of cancers, including colorectal, breast, lung, renal and gastric cancers ( 15 – 18 ). Depending on the disease state of cancer, patients have to face a 4 to 8 times greater risk of venous thrombosis or thromboembolism compared to patients without cancer ( 18 ).…”

The Application of the Lymphoma International Prognostic Index to Predict Venous Thromboembolic Events in Diffuse Large B-Cell Lymphoma Patients

“…Several risk assessments models (RAM) for chemotherapyassociated thrombosis attempted to identify patients at higher risk for VTE (10)(11)(12)(13). Due to poor discriminatory performance, particularly when studied on a single disease cohort, most of such models have proven to be of limited clinical utility (14)(15)(16)(17). Given these limitations, Antic et al developed and validated a new model, known as the Thrombosis Lymphoma (ThroLy) score, to predict thromboembolic events in lymphoma patients (18,19).…”

Ability of the Khorana score to predict recurrent thromboembolism in cancer patients with ischemic stroke

“…One could speculate that the score might predict venous thromboembolism more accurately than arterial events, although in secondary analysis restricted to venous thrombosis outcomes, the score’s discriminatory ability remained poor. Our study builds on the findings of recent studies in which the Khorana score did not accurately stratify the risk of thromboembolic events among patients with different cancer subtypes [17–19]. The Khorana score also does not incorporate data on stroke mechanisms and treatments, which are important predictors of thromboembolism recurrence.…”