Incidence of venous thromboembolism among chemotherapy-treated patients with lung cancer and its association with mortality: a retrospective database study.

Cancer patients, especially those with lung cancer and undergoing chemotherapy, have an elevated risk for venous thromboembolism (VTE). This study assessed incidence, timing, and risk factors for VTE (specifically receipt of chemotherapy), along with the association between VTE and survival among lung cancer patients receiving chemotherapy. Using Florida Medicaid administrative claims data (2000-2008), patients with any diagnosis of primary lung cancer were selected. Patients with recent prior VTE and those enrolled in Medicare or an HMO were excluded. Crude rates of VTE per 100 person years were estimated, and Cox proportional hazards models were developed to assess risk factors for VTE in the lung cancer population, and the association between VTE and survival among patients undergoing chemotherapy. Of 15,749 lung cancer patients, 7,052 (2,242 receiving chemotherapy and 4,810 not receiving chemotherapy) met cohort selection criteria. The incidence of VTE was 10.8 per 100 person-years (PYs) in the chemotherapy cohort and 6.8 per 100 PYs in the non-chemotherapy cohort. Among patients on chemotherapy developing VTE, median time to occurrence was 109 days, with 61 and 82 % of patients experiencing an event within six and 12 months, respectively. In multivariate analyses, the adjusted risk of VTE was 30 % higher among patients undergoing chemotherapy. Comorbidity and the presence of a central venous catheter also were significantly associated with a greater risk of developing VTE. Moreover, patients in the chemotherapy cohort who developed VTE had a significantly faster time-to-death (adjusted hazard ratio [HR] = 1.97; 95 % CI 1.69-2.29).VTE was common among lung cancer patients, especially among patients receiving chemotherapy, with the majority of VTE events occurring within 6 months of initiation of chemotherapy. The presence of a VTE event was significantly associated with an increased risk of mortality.