Abstract
Patients with two unprovoked venous thromboembolism (VTE) events could be at high
risk for cancer diagnosis and may therefore benefit from extended cancer screening
strategies. However, accurate data on the incidence of cancer in this population is
lacking. In a prospective cohort study, we followed-up with all patients who experienced
two unprovoked symptomatic VTE events that occurred in less than 2 years apart. We
estimated the 1-year incidence rate of cancer following the second unprovoked VTE
event using the Kaplan–Meier method. Potential predictors for cancer diagnosis were
assessed using a Cox proportional hazard regression model. Between May 2000 and December
2013, we included 197 patients with two episodes of symptomatic unprovoked VTE that
occurred in less than 2 years apart. Their mean age was 66.2 ± 16.3 years, and 122
(51.8%) were male. Seventeen patients were diagnosed with cancer during the year following
the second episode of unprovoked VTE, corresponding to a cumulative incidence rate
of 9.19% (95% confidence interval [CI]: 5.81–14.37). The 1-year cumulative incidence
rate of cancer was 35.88% (95% CI: 19.75–59.25) in patients with VTE recurrence on
anticoagulation, 5.51% (95% CI: 2.9–10.32) among patients with a second episode of
unprovoked VTE occurring after stopping anticoagulation and 1.15% (95% CI: 0.16–7.88)
when time elapsed between the first and recurrent VTE was > 1 year. Our study suggests
that the incidence of cancer in patients with a second episode of unprovoked VTE that
occurs off anticoagulation, or > 1 year after the first event, is similar to that
of patients with a first unprovoked VTE event.
Keywords
unprovoked venous thromboembolism - occult cancer - symptomatic VTE events
