Risk for vascular thromboembolic events (VaTEs) in patients (pts) with advanced urinary tract cancer (aUTC) treated with chemotherapy.

383 Background: Venous thromboembolism (VTE) is a frequent complication of cancer or its treatment. Khorana (KRS) and Compass scores are two Risk Assessment Models for VTE. However, aUTC was not adequately represented and arterial events were not included, in these models. Methods: Data from pts with aUTC treated with at least one line of chemotherapy in our institution were analyzed. VaTE definition included: DVT and PE defined as venous events and peripheral arterial thrombosis or embolus, ischemic stroke and coronary events, grouped as arterial events. The association of baseline and treatment-related factors with the development of VaTE was assessed using competing-risk regressions. According to the results of our multivariate analysis we stratified patients according to the number of the identified risk factors. Results: 354 aUTC pts treated between 4/1995 and 9/2015 entered our study. 53% of pts had received cisplatin and 42% carboplatin-based regimens. 44 pts (12.4%) suffered 45 VaTEs (13 arterial, 32 venous) within a median time of 3.3 months. The cumulative and 6-month incidence was 14.8% (95% CI: 10.9-19.4) and 9.7% (95% CI: 6.8-13.1), [venous 10.5% (95% CI: 7.3-14.3)/7.5% (95% CI: 5-10.7); arterial 5.3% (95% CI: 2.8-9)/2.7% (95% CI: 1.3-5), respectively]. No association of the KRS and the COMPASS score with the incidence of VaTEs was observed. In the univariate and multivariate analysis, cumulative VaTE incidence was significantly increased in pts with “peripheral arterial disease (PAD) or history of VΤE” (adjusted SHR: 3.29; 95% CI: 1.65-6.55; p=0.001) and pts with other solid tumor (SHR: 2.20; 95% CI: 1.05-4.62; p=0.038). There was a strong correlation between the number of risk factors and the risk for VaTE development (p<0.001). Patients with 1 or 2, vs 0 factors had a 3-fold increased risk [cumulative incidence was 10.9% (95% CI: 7.4.-15.2) and 30.2% (95% CI: 18.4-42.8), respectively; SHR: 3.01 95% CI: 1.65-5.51]. Conclusions: Development of tumor-specific algorithms for the risk of vascular events is supported by our results. Pts with aUTC and a history of VTE, PAD and other solid tumor have a very high risk for VaTE. The role of prophylaxis should be prospectively studied.