Development of a clinical prediction rule for risk stratification of recurrent venous thromboembolism in patients with cancer-associated venous thromboembolism.
BACKGROUND
Long-term low-molecular-weight heparin (LMWH) is the current standard for treatment of venous thromboembolism (VTE) in cancer patients. Whether treatment strategies should vary according to individual risk of VTE recurrence remains unknown. We performed a retrospective cohort study and a validation study in patients with cancer-associated VTE to derive a clinical prediction rule that stratifies VTE recurrence risk.


RESULTS
The cohort study of 543 patients determined the model with the best classification performance included 4 independent predictors (sex, primary tumor site, stage, and prior VTE) with 100% sensitivity, a wide separation of recurrence rates, 98.1% negative predictive value, and a negative likelihood ratio of 0.16. In this model, the score sum ranged between -3 and 3 score points. Patients with a score ≤ 0 had low risk (≤ 4.5%) for recurrence and patients with a score >1 had a high risk (≥ 19%) for VTE recurrence. Subsequently, we applied and validated the rule in an independent set of 819 patients from 2 randomized, controlled trials comparing low-molecular-weight heparin to coumarin treatment in cancer patients.


CONCLUSIONS
By identifying VTE recurrence risk in cancer patients with VTE, we may be able to tailor treatment, improving clinical outcomes while minimizing costs.
Department of Medicine, Division of Hematology, University of Western Ontario, 800-E3637 Commissioners Rd E, London, ON, Canada, N6A 5W9. martha.louzada@lhsc.on.ca
Martha L
ML
Louzada
Marc
M
Carrier
Alejandro
A
Lazo-Langner
Vi
V
Dao
Michael J
MJ
Kovacs
Timothy O
TO
Ramsay
Marc A
MA
Rodger
Jerry
J
Zhang
Agnes Y Y
AY
Lee
Guy
G
Meyer
Philip S
PS
Wells
D000925:Anticoagulants / Q000627:therapeutic use; D015331:Cohort Studies; D003374:Coumarins / Q000627:therapeutic use*; D003661:Decision Support Techniques; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009369:Neoplasms / Q000150:complications*; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D055502:Secondary Prevention; D012680:Sensitivity and Specificity; D054556:Venous Thromboembolism / Q000453:epidemiology* / Q000517:prevention & control*
D000925:Anticoagulants; D003374:Coumarins; D006495:Heparin, Low-Molecular-Weight; C030123:coumarin