Clinical factors and outcomes of subsegmental pulmonary embolism in cancer patients.

In the cancer population, patients diagnosed with venous thromboembolism (VTE) are considered to have a threefold increased risk of mortality compared with those without VTE. With the advent of modern computed tomography (CT), the rate of diagnosis of subsegmental pulmonary embolism (SSPE) has increased, likely as a result of improved visualization of the peripheral pulmonary arteries. The clinical significance of SSPE remains unclear because of the lack of randomized controlled clinical trials. The aim of this study was to identify the incidence and risk factors of recurrent proximal PE within 12 months of diagnosis of SSPE in cancer. We performed a retrospective analysis of 206 adult cancer patients who were diagnosed with SSPE from 2014 to 2016 at the University of Texas MD Anderson Cancer Center. At the time of SSPE diagnosis, the majority had metastatic cancer, 108 patients (53.2%) were undergoing chemotherapy, and 23 patients (11.2%) had a history of VTE. Most patients had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2. Sixty-seven percent of SSPE was discovered incidentally on restaging CT scans, with the majority being a single and isolated event (70.9%). Within 12 months of SSPE diagnosis, 18 patients (8.7%) were found to have a recurrent PE. The patients treated with anticoagulation had a lower rate of PE recurrence (8% vs 13% in those not treated with anticoagulation). Treatment with anticoagulation did not appear to have a significant impact on overall survival (P = .48) when adjusted for ECOG performance status and cancer stage.