2107P - Thromboprophylaxis with intermediate or prophylactic doses of LMWHs in ambulatory cancer patients

Background

Thromboembolic events occur in up to 20% of cancer patients during their course of disease. Cancer associated thrombosis (CAT) is a “signum malum” for cancer itself contributing to morbidity and mortality. Optimal measures to prevent CAT are crucial.

Methods

A post hoc analysis of GMaT & ACT4CAT prospective observational phase IV studies conducted in Greece by Hellenic Society for Medical Oncology (HeSMO), aiming to evaluate efficacy & safety of primary CAT prophylaxis with prophylactic (ProD) or intermediate (InterD; 50%-75% of full treatment dose) doses of Low Molecular Weight Heparins (LMWHs) in ambulatory active cancer patients. Both studies conducted according to Helsinki declaration.

Results

1157 patients from 26 oncology centers were recruited. Age: 64.9±12.3 years, BMI: 26.1±45.1 Kg/m², 59.9% males. Metastasis in 74.5%, Highly Thrombogenic Agents (HTAs) received 82.3%. Anticoagulation agents were (%): 91.2 tinzaparin, 4.6 fondaparinux, 2.3 bemiparin, 1.2 enoxaparin, 0.8 rivaroxaban or apixaban, for 5.1±3.3 months duration. 62% of patients received InterD (1^st, 2^nd, 3^rd,adjuvant & neoadjuvant: 62.4%, 67.3%, 69.8%, 44.1% &71.4% respectively, p=0.004). InterD preferred in men, in those with metastasis, HTAs treatment and receiving erythropoietin agents (ESA) while ProD in those with history of bleeding, heart or vascular, lung or metabolic disease, immobility, surgery, or radiotherapy. Detailed info in the table. Table: 2107P

32 patients (2.8%) had thrombotic events (20 in ProD, 11 in InterD, 1 dose unspecified) with higher risk in ProD (OR: 3.1, 95%CI:1.5-6.5, p=0.0021). 26 minor bleeding events reported (2.3%, no dose related difference, p=0.2424).

Conclusions

Common clinical oncology practice was to administer prophylaxis using in most cases LMWHs and frequently in InterD. Selection of anticoagulation dose was based on demographics, cancer characteristics, treatment type and patient medical history. InterD was found to be more efficacious and without safety concerns.

Clinical trial identification

GMaT: NCT03292107; ACT4CAT: NCT03909399.

Editorial acknowledgement

Dr. Abraham Pouliakis Senior Researcher, 2nd Department of Pathology, National and Kapodistrian University of Athens “ATTIKON”, University Hospital, Athens, Greece.

Legal entity responsible for the study

Hellenic Society of Medical Oncology (HeSMO), Athens, Greece.

Funding

Hellenic Society of Medical Oncology (HeSMO), Athens, Greece.

Disclosure

All authors have declared no conflicts of interest.