Multicenter, prospective, case-control, observational study on the influence of venous thromboembolism on patient outcome.

1554 Background: The association between venous thromboembolism (VTE) and cancer is well known. VTE represents the second cause of death in cancer patients. In some retrospective analysis, carried out using population and hospital-based registries, it has been reported that patients with cancer and VTE have a worse survival than those with cancer without VTE. Methods: MASTER ONCOLOGY is a prospective, multicenter, national, observational, case-control study specifically designed to identify VTE risk factors and to evaluate the influence of VTE on outcome of cancer patients with locally advanced or metastatic solid tumours. Patients in case (cancer patients with VTE) and control (cancer patients without VTE) groups have been matched for gender, age, cancer site, cancer histology and extension of disease. Information on patients, tumour characteristics, concomitant diseases, treatments, risk factors were registered. Survival data have been prospectively collected at 10 months and assessed through both Kaplan Meier method and Cox proportional hazards regression. Results: 611 patients were enrolled in the study by 51 Italian Centers. Of these, 237 cases and 339 controls were evaluable. The mean age was 64.7 (range 23-84) and 64.5 (range 41-87) years in cases and controls groups, respectively; the percentage of males was 43.0% and 41.9%. The most frequent tumour sites were colon, breast, lung, pancreas and stomach. Overall survival was statistically better for control patients as compared to case patients (p=0.0021). The raw HR was statistically significant: case patients had a risk of death 1.56 larger than controls (95% CI 1.23-1.98). Considering the complete model (using backward selection), the HR, due to patients status after adjustment for covariates, was 1.29 (95% CI 1.01-1.66). Conclusions: The study results demonstrate, for the first time, in a prospective and specifically designed study, that patients with cancer and VTE have a reduced survival compared to cancer patients without VTE.