The benefits of a diagnostic workup for occult cancer in patients with venous thromboembolism (VTE) are controversial. Our aim was to provide and validate a risk score for occult cancer in VTE patients.
We designed a nested case-control study within a cohort of VTE patients included in the RIETE (Registro Informatizado Enfermedad TromboEmbólica) registry from 2001-2014. Cases: cancer detected beyond the first 30 days after VTE and up for 24 months. Controls: VTE patients with no cancer in the same period.
Of 5,863 eligible patients, 444 (7.6%; (95%CI: 6.8 to 8.2%) were diagnosed with occult cancer. On multivariable analysis, variables selected were: male gender, age>70 years, chronic lung disease, anaemia, raised platelet count, prior VTE and recent surgery. We built a risk score assigning points to each variable. Internal validity was confirmed using bootstrap analysis. Proportion of patients scoring ≤2 points who had cancer was 5.8% (241/4,150) and in those scoring ≥3 points of 12% (203/1,713). We also identified score dividing by gender and age subgroups.
This is the first risk score that identified VTE patients at increased risk for occult cancer. Our score needs to be externally validated.