Thromboprophylaxis in surgically treated colorectal cancer patients with tinzaparin: Intermediate results from the Onco-CAST trial.

Abstract

e15611 Background: The incidence of Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE) after colorectal surgery is approximately 29% and 1.6% respectively. The incidence of asymptomatic postoperative DVT in colorectal cancer (CRC) patients has been reported as high as 20%, even under thromboprophylaxis. Thus, thromboprophylaxis after surgical treatment for CRC is crucial. Latest guidelines from International Initiative on Thrombosis and Cancer (ITAC 2019) recommend use of highest prophylactic dose of Low Molecular Weight Heparin (LMWH). Methods: Onco-CAST is a prospective, phase IV, observational, non-interventional cohort study evaluating a) current management approach for CRC surgical prophylaxis and b) efficacy and safety of tinzaparin at 8.000 Anti-Xa IU, once daily (OD), for at least one month post hospital discharge. Patients enrolled after signing informed consent. Onco-CAST was conducted by the Hellenic Society of Coloproctology. Results: Results from 175 CRC patients from 9 Onco Surgical Clinics are reported. Participation completed 79% of patients at report time: 66% males, 67±12 years, BMI: 27.4±5.5. Histology: adenocarcinomas NOS 81%, mucinous adenocarcinomas 9%, small cell neuroendocrine carcinomas 2%, and others. High grade differentiation indicated: 26% and 5% metastatic. 32% treated with right hemicolectomy, 20% with low anterior resection, 12% with sigmoid colectomy, 9% with abdominal-perineal resection, 9% with left hemicolectomy and other methods. 67% treated open and 33% laparoscopic while the median number of lymph nodes dissected for left and right hemicolectomy was 32.5 (Q1-Q3:26-38) and 24 (Q1-Q3: 14.5-32), p = 0.0253. Factors related to thrombosis risk are presented in table, notably, 95% of patients accumulated ≥3 risk factors. Median thromboprophylaxis duration with tinzaparin 8.000 Anti-Xa IU, OD, was: 37 days (1st-3rd quartile: 33-45 days). Three thrombotic events occurred (efficacy 98.3%, 95% CI: 95.1-99.4%), one DVT+PE, one DVT and one due to Central Venous Catheter (CVC). Eight patients experienced bleeding events (4.6%, 95%CI: 2.3-8.8%), 3 minor, 3 major and 2 CNMB, 2 had a possible relation to thromboprophylaxis (1.1%, 95%CI: 0.3-4.1%). Conclusions: Thromboprophylaxis in Surgically Treated Colorectal Cancer Patients with Tinzaparin intermediate dose seems safe and efficient approach.[Table: see text]