Venous thromboembolism is a relevant and underestimated adverse event in cancer patients treated in phase I studies

Background: To investigate, retrospectively, the role of tumour histotype and antiangiogenic drugs for venous thromboembolism (VTE) development in advanced cancer patients treated in phase I studies. Methods: Patients enrolled and treated in phase I studies conducted by SENDO (Southern Europe New Drugs Organisation) were considered. Results: Data of 1415 patients were included in the analysis: 526 (37.2%) patients were males, median age was 57.3 years (range: 13–85). Fifty-six (3.96%) patients developed a VTE. At multivariate analysis gynaecologic (hazard ratio (HR): 2.8, 95% confidence interval (CI): 1.29–6.23, P=0.009) and gastrointestinal tumours (HR: 3.23, 95% CI: 1.18–8.87, P=0.023) as well as combination regimens of cytotoxic and antiangiogenic agents (HR: 2.6, 95% CI: 1.11–6.30, P=0.028), white blood cell >11 000 μl−1 (HR: 2.59, 95% CI: 1.10–6.09, P=0.028) and haemoglobin