ONKOTEV Risk Prediction Score for VTE in Cancer Patients

There are myriad clinical risk scores used to assess the VTE risk in patients with cancer. For example, the Khorana score has been validated in multiple settings and is recommended by most international guidelines. However, the underlying recommendation many of these scores are based on - primary thromboprophylaxis - has not been broadly adopted due to an unclear risk-benefit ratio.

In an article published in JAMA Oncology in February 2023, Cella et al. have published validation of a new risk prediction model with the ONKOTEV-2 study for outpatients with cancer.

473 patients from three European centres were screened for the study. 1 point was assigned to each of the four variables contributing to the ONKOTEV score (Khorana score >2, metastatic disease stage, presence of encasement or direct infiltration of vascular or lymphatic structures by gross tumour, and positive history for previous thromboembolic events).

The most represented tumours were breast (77 [18.1%]), gastro-oesophageal adenocarcinoma (70 [16.5%]), colon (54 [12.7%]), lung (47 [11.1%]), rectum (46 [10.8%]), and pancreatic cancers (32 [7.5%]).

Overall, VTEs occurred with a rate of 1.1 event-times per 100 person-months. Ninety-one patients (21.4%) died: 72 (16.9%) with death as a first event and 19 (4.5%) with VTE as a first event.

A total of 4 VTEs (3.4%) were diagnosed among the 116 patients with an ONKOTEV score of 0, 26 VTEs (11.1%) were diagnosed among the 234 patients with an ONKOTEV score of 1, 21 VTEs (32.8%) were diagnosed among the 64 patients with an ONKOTEV score of 2, and 3 VTEs (27.3%) were diagnosed among the 11 patients with an ONKOTEV score of greater than 2.

Metastatic disease (HR 4.22; P = .003) and macroscopic vascular or lymphatic compression (HR, 3.25; P < .001) were found to be highly associated with VTE. Similarly, patients with a Khorana score greater than 2 seemed to have a higher risk of VTE, although the difference was not statistically significant (HR, 1.81; P = .14). Previous VTE did not appear to be independently associated with the risk of VTE (HR, 0.84; P = .76) in this validation cohort.

So, if you have an outpatient with cancer who you need to assess for risk of VTE, or to assess the benefit of primary thromboprophylaxis, consider using the ONKOTEV score.

Source: Cella CA, Knoedler M, Hall M, et al. Validation of the ONKOTEV Risk Prediction Model for Venous Thromboembolism in Outpatients With Cancer. JAMA Netw Open. 2023;6(2):e230010. doi:10.1001/jamanetworkopen.2023.0010.
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