1670MO - Validation of a new risk-assessment model for prediction of venous thromboembolism in cancer outpatients: The ONKOTEV score

Background

The assessment of Venous Thromboembolism (VTE) risk in cancer outpatients still represents an evolving topic. Current international guidelines recommend an intermediate to high-risk group as identified by a Khorana score (KS) ≥ 2 as the cut-off for considering primary prophylaxis. In the previously reported prospective ONKOTEV study, we developed a 4 variables risk-assessment-model (RAM): KS > 2, metastatic disease, vascular/lymphatic compression and previous VTE. The goal of the current study is to validate the ONKOTEV score as a novel RAM in an independent cohort.

Methods

ONKOTEV-2 is a prospective, observational study conducted in Italy, Germany, and United Kingdom from May 2015 to September 2019. Clinical, laboratory and imaging data were collected at baseline, to calculate the ONKOTEV score before any cancer treatment. Each patient was followed up for 8 months, to detect VTE, by clinical examination and/or imaging performed in the routine practice.

Results

Overall, 473 patients were included in the study. The most common primary sites in all cohorts were breast, esophagus/stomach, colon, rectum, lung and pancreas. In accordance with the KS, the population study was stratified into the following risk categories: low (58%), high (18%) and very-high (24%). In accordance with the ONKOTEV score, 27 %, 55%, 15% and 2.4% of patients had 0, 1, 2 and 3 score, respectively. Overall, the cumulative incidence (CI) of VTE was 12.7%. The CI for the risk of developing VTE by KS and ONKOTEV score is shown in the table. Table: 1670MO

Cumulative incidence function (at 12 months) for the risk of VTE by Khorana and ONKOTEV score

Conclusions

ONKOTEV score ≥ 2 identified a category of high-risk group of cancer outpatients and significantly improved the VTE predictability of pre-existing RAMs. Therefore, ONKOTEV score has been validated as a new easy-to-use RAM for risk stratification and decision making about primary prophylaxis in cancer outpatients, with promising implications in clinical practice. The study was awarded within the EORTC Young Investigator program (2015-2018).

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

C.A. Cella.

Funding

EORTC.

Disclosure

All authors have declared no conflicts of interest.