Incidence, risk factors and clinical implications of venous thromboembolism in cancer patients treated within the context of phase I studies: the 'SENDO experience'

Background: To investigate the incidence, risk factors and clinical implications of venous thromboembolism (VTE) in advanced cancer patients treated in phase I studies. Patients and methods: Patients enrolled and treated in phase I studies conducted by SENDO (Southern Europe New Drugs Organization) Foundation between 2000 and 2010 in 15 experimental centers were considered for the study. Clinical data, including adverse events, were prospectively collected during the studies and retrospectively pooled for VTE analysis. Results: Data of 1415 patients were considered for analysis. Five hundred and twenty-six (37.2%) patients were males, and median age was 57.3 years (range: 13-85). Eighty-five percent of patients had metastatic disease, while the remaining had locally advanced irresectable disease. For 706 (49.9%) of the patients, the study treatment was with cytotoxic agent(s) only, for 314 with target therapy(ies) only, while the remaining patients received a target therapy in combination with a cytotoxic drug. Fifty-six (3.96%) patients who developed a VTE, almost all (89.3%) during the course of treatment, the remaining during the follow-up. At univariate analysis, the Khorana score, the combination of an antiangiogenic agent with a cytotoxic drug, and the time from first cancer diagnosis to study entry (as continuous variable) were associated with a statistically significant increase of VTE occurrence. The multivariate analysis confirmed only a statistically significant association for the Khorana score. The hazard ratio of VTE occurrence was 7.88 [95% confidence interval (CI) 2.86-21.70) and 2.74 (95% CI 1.27-5.92) times higher for the highest (>= 3) and intermediate (1-2) scores as compared with score = 0. Conclusions: VTE is a relatively common complication among patients treated in the context of phase I studies. The Khorana score predicts VTE development and can be used to identify patients at high of VTE.