Validation of the Khorana score in acute myeloid leukemia patients: a single-institution experience

Abstract

Background Although patients with acute myeloid leukemia (AML) were shown to have an increased risk of thrombosis, no thrombosis risk assessment scoring system has been developed for AML patients. The Khorana Risk Score (KRS), which has been widely used for thrombosis risk assessment in the clinical setting, was developed on the basis of solid tumor data and has not been validated among AML patients. This study aims to validate the use of the KRS as a thrombosis risk-scoring system among patients with AML. Methods Using data from H. Lee Moffitt Cancer Center and Research Institution’s Total Cancer Care Research Study, we retrospectively identified patients who were histologically confirmed with AML from 2000 to 2018. Clinical and laboratory variables at the time of AML diagnosis were characterized and analyzed. The thrombotic event rate was estimated with the Kaplan-Meier method and compared using the log-rank test. Results A total of 867 AML patients were included in the analysis. The median age at AML diagnosis was 75 years (range, 51–96), and the majority were male (65%, n = 565). A total of 22% ( n = 191), 51% ( n = 445), 24% ( n = 207), and 3% ( n = 24) of patients had a KRS of 0, 1, 2, and 3, respectively. A total of 42 thrombotic events (3% [ n = 6/191] with a KRS of 1; 5% [ n = 23/445] with a KRS of 2; 6.3% [ n = 13/207] with a KRS of 3) were observed, with a median follow-up of 3 months (range, 0.1–307). There was no statistical difference in the risk of thrombosis between these groups ( P = .1949). Conclusions Although there was an increased risk of thrombosis associated with a higher KRS among AML patients with a KRS of 1 to 3, the difference was not statistically significant. Furthermore, only a few patients were found to have a KRS > 3, and this was largely due to pancytopenia, which is commonly associated with AML. These results indicate the need for a better thrombotic risk-scoring system for AML patients.

Prevention of Venous Thromboembolism in 2020 and Beyond

“…The Khorana score is also valid for use in hospitalized cancer patients [165,166]. Attempts to validate the Khorana score for specific subpopulations of cancer have been less successful, and in studies of lung cancer, hepatocellular carcinoma, acute myeloid leukemia, and lymphoid malignancies, the Khorana score did not adequately stratify or predict VTE events [167][168][169][170].…”

Risk factors of thrombosis in Chinese subjects with acute promyelocytic leukemia

“…Thrombosis risk is well defined in patients with solid tumors, and Khorana score is well validated for these patients. However, the value of Khorana scoring system in predicting the thrombotic events risk of hematological malignant diseases remains to be evaluated [ 29 , 30 ]. Hence, we conducted a retrospective study to validate the use of the Khorana score for thrombotic events in APL patients.…”

‘Catastrophic’ Thrombosis in a Young Patient With Acute Myeloid Leukemia Presenting Early in the COVID-19 Pandemic – A Case Report

“…To date, there are few clinical and laboratory parameters that have been shown to improve our ability to identify those patients at highest risk for thrombotic complications, and a widely-validated and useful clinical predictive rule is currently an unmet need. The Khorana risk score, a model developed to stratify thrombotic risk in patients with solid tumors, did not accurately predict thrombosis in patients with AML using clinical and laboratory values at diagnosis in a retrospective cohort of 867 patients, perhaps because of the large number of patients presenting with pancytopenia (5). Recently, a clinical predictive rule for development of venous thromboembolism in patients with acute leukemia was proposed based on three statistically significant variables: Personal history of venous thromboembolism, acute lymphoblastic leukemia and platelet count >50,000×10 3 /mm 3 at baseline); the model was internally validated in a single institution but awaits more extensive validation (6).…”