How it's calculated
Cancer site contributes 0-2 points, and four additional lab/clinical factors each contribute 1 point, for a total of 0-6, estimating venous thromboembolism (VTE) risk over the course of chemotherapy.
Score interpretation
| Score | VTE risk |
|---|---|
| 0 | Low |
| 1-2 | Intermediate |
| ≥3 | High |
Clinical use
- Used to identify ambulatory cancer patients starting chemotherapy who may benefit from primary thromboprophylaxis, weighed against individual bleeding risk.
- Guideline bodies (ASCO, NCCN) generally reserve consideration of pharmacologic prophylaxis for intermediate-to-high risk patients without contraindications.
- The score does not replace individual clinical judgement about bleeding risk, drug interactions, and patient preference when deciding on prophylaxis.
- Was derived and validated in an ambulatory chemotherapy population — it is not intended for hospitalised or postoperative cancer patients, who have separate risk-assessment tools.
Frequently asked questions
What is the Khorana Score used for?
It estimates the risk of venous thromboembolism in ambulatory cancer patients starting chemotherapy, helping identify those who may benefit from prophylactic anticoagulation.
What counts as 'very high risk' cancer sites?
Stomach and pancreatic cancers carry the highest independent VTE risk and are scored 2 points; lung, lymphoma, gynaecologic, bladder, and testicular cancers are scored 1 point.
Does a high score mean a patient should be started on anticoagulation?
Not automatically — it identifies patients who may benefit from prophylaxis, but bleeding risk, drug interactions, and clinical context must also be considered before starting anticoagulation.
Is this score used for hospitalised cancer patients?
No — it was derived for ambulatory patients starting chemotherapy. Hospitalised and postoperative cancer patients are assessed with separate VTE risk tools.
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.
- Key NS, Khorana AA, Kuderer NM, et al. Venous thromboembolism prophylaxis and treatment in patients with cancer: ASCO guideline update. J Clin Oncol. 2020;38(5):496-520.