Risk and Timing of Venous Thromboembolism After Surgery for Lung Cancer: A Nationwide Cohort Study

BACKGROUND Venous thromboembolism (VTE) is a potentially preventable serious complication in lung cancer patients undergoing thoracic surgery. We examined the risk and timing of VTE following surgery for primary non-small cell lung cancer (NSCLC). METHODS: in the Danish Lung Cancer Registry. VTE events in the year after surgery were assessed by stage, patient characteristics, and surgical procedure. RESULTS We identified 13,197 patients who underwent surgery for NSCLC in 2003-2021 (mean age 67.6 years, 50% female); 10,524 (79.7%) had stage I-II NSCLS and 2673 (20.3%) had stage III-IV. During one-year follow-up, there were 335 VTE events, yielding a rate of 2.87 events/100 person-years and an absolute risk of 3.3% (95% CI 2.3-4.0). VTE risk increased with advancing cancer stage (1.8% for stage I versus 4.1% for stage IV), but varied little by pathological type, sex, and comorbidity level. Bilobectomy was associated with highest VTE risk (4.8%, 95% CI 3.2-6.9), followed by pneumonectomy (3.6%, 95% CI 2.5-5.1). The hazard of VTE was highest during the first three months after surgery, whereafter it declined. For stage IV cancer hazards increased again after six months. At one-year, all-cause death was 12.6% (95% CI: 12.0-13.1 %). CONCLUSIONS Among patients undergoing surgery for NSCLC, 3.3% developed VTE, most commonly within 3 months postoperatively. Prolonged thromboprophylaxis could be considered, particularly in those with advanced cancer stage and undergoing extended resections.