Khorana score for chemotherapy-associated venous thromboembolism
VTE risk before chemotherapy, from tumour site and pretreatment labs.
Switch how results are explained
Low risk (score 0). Thromboprophylaxis is not indicated; educate on the symptoms of thrombosis.
- Evidence grade
- B
What it is and when to use it
The Khorana score adds tumour site (0, 1 or 2 points by risk category) to four pretreatment variables - platelet count, haemoglobin or ESA use, leukocyte count and BMI - to estimate the risk of venous thromboembolism before starting chemotherapy.
How to interpret it
A score of 0 is low risk, 1–2 intermediate, and 3 or above high risk. Guidelines recommend considering pharmacological thromboprophylaxis in high-risk patients without a contraindication from bleeding risk.
Limitations and when not to use it
This is a screening tool for ambulatory patients starting chemotherapy; it does not apply to inpatients or to managing an established VTE event. The final decision to start prophylaxis must weigh individual bleeding risk and the specific chemotherapy regimen.
Formulas and cut-offs are from the original authors of each score; see the references.
Last reviewed: June 2026
References
- Khorana AA, Kuderer NM, Culakova E, Lyman GH, Francis CW. Development and validation of a predictive model for chemotherapy-associated thrombosis. Blood. 2008;111(10):4902-4907. PMID:18216292