Unsuspected pulmonary emboli in lung cancer patients: The impact on survival and the significance of anticoagulation therapy

BackgroundMany pulmonary emboli (PE) are detected unsuspectedly in lung cancer patients. The purpose of our study was to retrospectively evaluate the role of anticoagulation therapy for unsuspected PE in lung cancer patients. We also aimed to evaluate risk factors associated with the development of PE as well as the prognostic power of PE in lung cancer patients.Patients and methodsThe Samsung Medical Information System was used to evaluate predictors and prognosis of PE in lung cancer patients. We found patients with PE using the Radiation Interpretation Registry and reviewed their medical records.ResultsAmong 8014 lung cancer patients, PE developed in 180 patients (cumulative incidence rates = 2.2%). Metastasis and prior history of chemotherapy were significant predictors of the development of PE. Pulmonary embolism detected within 3 months after diagnosis of lung cancer was a significant poor prognostic factor (hazard ratio [HR], 1.5; 95% CI, 1.1–2.0) in the complete lung cancer cohort. One hundred thirteen (63%) out of total 180 PE patients were incidentally found to have PE. Among the 113 patients with unsuspected PE, 62 patients (55%) did not receive anticoagulation therapy, and died sooner than those who received anticoagulation therapy for unsuspected PE (HR, 4.1; 95% CI, 2.3–7.6).ConclusionAnticoagulation therapy for unsuspected PE is associated with increased overall survival in lung cancer patients.