Venous thromboembolism in surgical lung cancer patients: a provincial population-based study

Background — Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in surgical patients. Thoracic surgery patients are at increased risk due to inherent technical and disease-specific factors. Other surgical specialties have adopted post-discharge extended VTE prophylaxis; however, evidence is scarce in thoracic surgery. This study aims to identify VTE risk factors and associated mortality among surgical lung cancer patients.

Methods — Using administrative databases, all patients in the province of Ontario undergoing lung cancer surgery from 2007 to 2017 were identified. Logistic regression identified VTE risk factors at 90-days and one-year postoperatively. A flexible parametric survival analysis compared mortality and survival up to 5 years after surgery between patients with and without VTE.

Results — Of 65,513 patients diagnosed with lung cancer, 12,626 (19.3%) underwent surgery. VTE incidence at 90-days and 1-year postoperatively was 1.3% and 2.7%, respectively. Open and more extensive resections carried an increased VTE-risk, with pneumonectomy conferring the highest risk (OR = 2.36; p<0.001). Stage III and IV disease carried a 3.19 and 4.97-times higher risk of VTE, respectively, compared to stage I (p<0.001). The hazard ratio for mortality at one year for patients with a VTE was 2.01 (p<0.001). Patients suffering a VTE had reduced 5-year survival.

Conclusions — Patients undergoing pneumonectomy and those with advanced stage have an increased VTE-risk. Patients suffering a thrombotic complication have an increased risk of mortality, and decreased 5-year survival. Accordingly, strategies to reduce VTE risk should be considered in patients undergoing high risk operations to reduce the mortality of VTEs.