Development of a Risk Prediction Score for Occult Cancer in Patients With VTE

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