Venous thromboembolism in patients with cancer: design and rationale of a multicentre, prospective registry (Cancer-VTE Registry).

INTRODUCTION: Patients with cancer are at higher risk of venous thromboembolism (VTE) than the general population as the malignancy itself and treatment modalities, including medication and surgery, contribute to the risk of developing VTE. Furthermore, patients with cancer developing VTE have a worse prognosis than those without cancer. There are no multicentre prospective data on the occurrence and treatment of VTE in patients with cancer in Japan, and data on the outcomes, complications and incidence of VTE in these patients have not been reported. In addition, Japanese patients with cancer are traditionally treated with unfractionated heparin or warfarin; however, the use of direct oral anticoagulants, which became available in 2014, has not been sufficiently examined in this patient group. Therefore, this multicentre, prospective registry has been designed to capture VTE data from Japanese patients presenting with six cancer types.

METHODS AND ANALYSIS: This registry will enrol 10 000 patients with colorectal, lung, stomach, breast, gynaecological (including endometrial, cervical, ovarian, fallopian tube and peritoneal) or pancreatic cancer between March 2017 and March 2019 and follow them for 1 year. We plan to collect data on the incidences of symptomatic VTE, bleeding events, stroke, systemic embolic events, incidental VTE requiring treatment in patients, overall survival and symptomatic VTE event-free survival.

ETHICS AND DISSEMINATION: All patients will provide written informed consent. Data will remain anonymous and will be collected using an online electronic data capture system. Study protocol, amendments and informed consent forms will be approved by the institutional review board/independent ethics committee at each site prior to study commencement. Results will be disseminated at national meetings and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER: UMIN000024942.