The Khorana Score in Predicting Venous Thromboembolism for Patients With Metastatic Urothelial Carcinoma and Variant Histology Treated With Chemotherapy

Abstract : Background: The Khorana score is a predictive risk model for venous thromboembolism (VTE) in patients with cancer planning to receive chemotherapy. Urothelial carcinoma and variant histologies (UC/VH) were underrepresented in the model. We sought to evaluate whether the Khorana score predicts for VTE in a retrospective multinational data set of patients with metastatic UC/VH. Methods: Patients diagnosed with metastatic UC/VH who received chemotherapy were eligible. Those with incomplete or miscoded data were excluded. Khorana scores were calculated based on the pretreatment data and categorized into high (≥3) or intermediate (1-2) VTE risk. Other patient-, tumor-, and therapy-related factors were also analyzed. The χ2 and logistic regression analyses were used to assess differences in VTE rates based on the clinical characteristics. Subgroup analyses were performed to evaluate the Khorana score and associated variables for early (<3 months) and late (>3 months) VTE. Results: A total of 943 patients were eligible for analysis. The cumulative VTE rate was 9.9%. There was no statistical difference in overall VTE rate between Khorana high- and intermediate-risk groups (P = .16). In the multivariate analysis, nonurothelial histology (odds ratio [OR] = 2.56; P = .002) and the presence of cardiovascular disease (CVD) or CVD risk factors (OR = 2.14; P = .002) were associated with increased VTE risk. In the first 3 months from initiation of chemotherapy, Khorana high risk (OR = 2.08; P = .04) was associated with higher VTE rates. White blood cell (WBC) count (OR = 1.05; P = .04) was the only significant Khorana variable for early VTE. Conclusions: The Khorana score stratifies early but not overall VTE risk in patients with metastatic UC/VH. The WBC count drives the increased early VTE risk seen with the Khorana score.