Development and validation of a predictive model for chemotherapy-associated thrombosis

Area of Science:

• Oncology
• Hematology
• Clinical Medicine

Background:

• Cancer patients have an increased risk of venous thromboembolism (VTE).
• Existing risk factors are insufficient to identify high-risk outpatients for preventative anticoagulation (thromboprophylaxis).

Purpose of the Study:

• To develop and validate a simple clinical model for predicting chemotherapy-associated VTE in cancer outpatients.
• To identify key clinical and laboratory variables associated with VTE risk.

Main Methods:

• A prospective observational study enrolled 2701 cancer outpatients in a derivation cohort and 1365 in a validation cohort.
• A multivariate model was developed using baseline clinical and laboratory data.
• Key predictors included cancer site, platelet count, hemoglobin levels, leukocyte count, and body mass index.

Main Results:

• The validated risk model identified five key predictors: cancer site, platelet count (≥350 x 10^9/L), hemoglobin (<100 g/L) and/or ESA use, leukocyte count (>11 x 10^9/L), and BMI (≥35 kg/m^2).
• VTE rates over 2.5 months were 0.8% (low-risk), 1.8% (intermediate-risk), and 7.1% (high-risk) in the derivation cohort, and 0.3%, 2%, and 6.7% in the validation cohort, respectively.
• The model demonstrated good predictive accuracy (C-statistic = 0.7) in both cohorts.

Conclusions:

• A simple, validated model effectively identifies cancer outpatients at high risk for short-term VTE (nearly 7%).
• This model can aid in selecting appropriate candidates for thromboprophylaxis studies and potentially clinical practice.