1858P - Efficacy and safety of thromboprophylaxis in oncology patients with Khorana score<2: Combined results from GMaT and ACT4CAT studies

Background

Cancer incidence is rising, and cancer associated thrombosis (CAT) remains a common and potentially fatal complication among cancer patients. Risk stratification tools have been developed. The Khorana score (KS) was foundable to risk-stratify ambulatory patients initiating chemotherapy, but only for selected cancer types, challenging its universal application.

Methods

A post hoc analysis of GMaT and ACT4CAT, prospective observational phase IV studies conducted by Hellenic Society for Medical Oncology (HeSMO) in Greece, aiming to evaluate efficacy and safety of thromboprophylaxis in oncology patients with KS<2 and to identify parameters that drive oncologists’ decision to administer prophylaxis to them. Both studies were conducted according to Helsinki declaration.

Results

From 1157 patients recruited from 26 oncology centers 478 (41.3%) had KS30 History of Thrombosis History of Surgery History of heart or vessel disease Comorbidities % Head & neck 3.1 30.0 63.6 80.0 73.3 33.3 80.0 33.3 0.0 66.7 46.7 53.3 Lung 22.0 21.7 84.7 84.8 34.3 61.0 83.8 21.0 2.9 31.4 37.1 47.6 Breast 13.2 98.4 65.6 52.4 48.3 36.5 31.8 20.6 8.2 71.4 35.7 57.6 Colorectal 18.2 43.2 80.0 87.4 15.1 57.5 49.4 13.8 5.8 51.7 34.4 47.7 Urothelial 18.8 9.3 73.3 65.2 18.9 67.8 72.2 20.0 8.9 49.4 43.1 50.0 Female reproductive system 6.3 100.0 48.3 86.7 6.7 70.0 23.3 36.7 3.3 66.7 35.7 55.2 Others 18.4 43.8 58.2 64.4 24.4 52.3 58.0 19.3 5.7 56.8 26.3 47.7

Anticoagulation agents used (%): 90.4 tinzaparin, 3.8 fondaparinux, 2.9 bemiparin, 1.3 enoxaparin, 0.8 rivaroxaban & apixaban, for 5.0±3.4 months duration. Thrombotic events (10 DVT, 3 PE, 2 ATE) occurred in 15 of 478 patients (3.1%) with Khorana score

Conclusions

While the reductionist design of Khorana score supports its applicability, it does not include other risk factors for CAT such as histology, stage of disease and type of treatment. Presence of metastasis and use of HTAs treatments apart from KS were also found guiding primary CAT prophylaxis in patients with KS<2 using primarily low molecular weight heparins (LMWHs). Thromboprophylaxis in high-risk oncology patients with KS<2 seems to be safe and effective.

Clinical trial identification

NCT03292107 ACT4CAT, NCT03909399.

Editorial acknowledgement

A. Pouliakis.

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.