The Khorana score in predicting venous thromboembolism for metastatic urothelial carcinoma and variant histology patients treated with chemotherapy

Abstract

Background

The Khorana score is a predictive risk model for venous thromboembolism (VTE) in cancer patients planning to receive chemotherapy. Urothelial carcinoma and variant histologies (UC/VH) were underrepresented in the model. We sought to evaluate if the Khorana score predicts for VTE in a retrospective multinational dataset of metastatic UC/VH patients.

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 pre-treatment data and categorized into high (≥3) or intermediate (1-2) VTE risk. Other patient, tumor, and therapy related factors were also analyzed. Chi-squared and logistic regression analyses were utilized to assess differences in VTE rates based on clinical characteristics. Subgroup analyses were performed to evaluate the Khorana score and associated variables for early (<3 months) and late (>3 months) VTE.

Results

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=0.16). In the multivariate analysis, non-urothelial histology (OR=2.56,P=0.002) and the presence of cardiovascular (CVD) or CVD risk factors (OR=2.14,P=0.002) were associated with increased VTE risk. In the first 3 months from initiation of chemotherapy, Khorana high-risk (OR:2.08,P=0.04) was associated with higher VTE rates. White blood cell (WBC) count (OR:1.05,P=0.04) was the only significant Khorana variable for early VTE.

Conclusions

The Khorana score stratifies early, but not overall VTE risk in metastatic UC/VH patients. WBC count drives the increased early VTE risk seen with the Khorana score.