Real world data for venous thromboembolisms (VTEs) in patients with active cancer: Thromboprophylaxis pooled analysis from GMaT and ACT4CAT studies.

Abstract

6637 Background: Venous Thromboembolisms (VTEs) lead to many negative consequences for patients with active cancer and are reported up to 20%. They affect anticancer treatment plan, increase morbidity, mortality, economic burden, and escalate psychological drain. Current guidelines recommend pharmacologic prophylaxis for thrombosis in ambulatory cancer patients with Khorana score ≥2. Methods: GMaT and ACT4CAT are prospective observational phase IV studies conducted by HeSMO in Greece. The aim was to record the clinical practice for ambulatory patients with active cancer who received thromboprophylaxis and enrolled after signing informed consent. Studies were approved by the bioethics committee. Results: 1157 patients from 26 oncology clinics enrolled who received thromboprophylaxis. Tumor types: gastrointestinal 38.5%, lung 24.8%, urological 12.2%, gynecological 6.9%, breast 6.1% and others 11.5%. Treatment lines: 1st 62.5%, 2nd 15.1%, 3rd 4%, adjuvant 9.7% and neoadjuvant 5.9%. Age ≥65 in 55.2%, BMI ≥30 in 17.8% and males 59.9%. High-Risk for Thrombosis Agents (HRTAs) received 82.3%: platinum agents (52.9%), antimetabolites (49.0%) and immunotherapy (10.2%). Notably, 52.7% of anticancer agents had potential drug-drug interactions (DDIs) with Direct Oral Anticoagulants (DOACs). High thrombotic risk factors presented in table. Thromboprophylaxis duration was 5.1±3.3 months with: tinzaparin 91.2%, fondaparinux 4.6%, bemiparin 2.3%, enoxaparin 1.2%, rivaroxaban 0.4% and apixaban 0.3%. Intermediate thromboprophylaxis doses of Low Molecular Weight Heparins (LMWHs) received 62% of patients; 50% in adjuvant setting & 72.6% in metastatic. 32 thrombotic events reported (efficacy: 97.2%, 95%CI: 96.3-98.2%) and 26 grade 1 or minor bleedings (2.2%, 95%CI:1.4-3.1%). Patients receiving intermediate doses of LMWHs had less risk for thrombosis (p=0.0308). Conclusions: VTEs prophylaxis in ambulatory patients with active cancer was found safe and effective. Apart from Khorana score, metastasis, HRTAs and DDIs seem to affect clinical decision for thromboprophylaxis mainly with LMWHs and often using intermediate doses irrelevant of clinical setting. Cancer Associated Thrombosis (CAT) is not negligible risk for patients and oncologists appeared to be aware about this. Clinical trial information: NCT03292107 , NCT03909399 . [Table: see text]