1772PPrevalence of venous thromboembolism based on intensive screening for patients with advanced solid tumor in prospective observational study

Abstract Background Venous thromboembolism (VTE) is frequently observed in patients with solid tumor. Previous report suggested that the prevalence of VTE varied among different ethnic groups. The objectives of this prospective observational study are to estimate the prevalence of VTE in Japanese patients with advanced solid tumor based on intensive screening, using CT scans, lower-extremity ultrasonography, and D-dimer testing. Methods Eight-hundred sixty Japanese patients were enrolled into this study. Adult (age ≥20 years) patients with metastatic or locally advanced solid tumor without anticoagulant therapy, who are planning to receive chemotherapy during 4 weeks, PS 0-2 were eligible in this study. Evaluations of VTE were performed at enrollment, 12 and 24 weeks. Primary endpoint was the prevalence of VTE for 24 weeks, and secondary endpoints included the incidence of VTE (at enrollment, 12 weeks, 24 weeks), VTE for 24 weeks by primary cancer site, symptomatic VTE for 24 weeks, pulmonary thromboembolism (PE), treatment of VTE. Results The median age was 68 years (range 28-96 years), 34% female, 46/45/8% performance status 0/1/2. Primary cancer site included lung (71%), gastrointestinal (GI) (15%), hepatobiliary and pancreatic (HP) (5%), and gynecological (3%). The prevalence of VTE for 24 weeks was 22.6% (95%CI: 19.8-25.5%). The incidences of VTE were 11.3% (97/858) at enrollment, 16.8% (134/799) at 12 weeks, 14.1% (101/716) at 24 weeks. Among 761 patients without VTE at enrollment, 97 (12.7%) showed VTE after the start of chemotherapy. The prevalence of VTE for 24 weeks was 24.1% in patients with lung, 17.7% with GI, 25.6% with HP, and 32.1% in gynecological cancer. Symptomatic VTE for 24 weeks was observed in 4.0%, and PE was in 1.0%. Treatment of anticoagulant for VTE was started in 15.0% (129/858) after enrollment in this study. Conclusions This prospective observational study showed that prevalence of VTE was relatively high in Japanese patients with advanced solid tumor under intensive screening, compared with previous reports. Although most of patients with VTE were asymptomatic, prophylactic anticoagulant therapies may be considered in this study population. Clinical trial identification UMIN000015243. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.