OC 03.3 - A new cancer-associated thrombosis risk score improves identification of high-risk patients: external validation in a large population-based cohort study

Saturday, June 22, 2024

13:30 – 13:45 ICT

Room: Ballroom B3

Presenting Author(s)

Vincent Lanting, MD

PhD student
Department of Vascular Medicine, Amsterdam University Medical Center, Amsterdam, The Netherlands
Amsterdam, Noord-Holland, Netherlands

Co-Author(s)

EV

Emese Vágó

PhD
Department of Clinical Epidemiology, Aarhus University Hospital and Aarhus University, Aarhus, Denmark
Aarhus, Hovedstaden, Denmark
EH

Erzsébet Horváth-Puhó

MSc, PhD
Department of Clinical Epidemiology, Aarhus University Hospital and Aarhus University, Aarhus, Denmark
Aarhus, Hovedstaden, Denmark
FM

Frits Mulder

Resident in Internal Medicine
Depertment of Vascular Medicine, Amsterdam University Medical Center, Amsterdam, The Netherlands
Amsterdam, Noord-Holland, Netherlands
MD

Marcello Di Nisio

Associate Professor, Internist
Department of Medicine and Ageing Sciences, “G D’Annunzio” University, Chieti, Italy
Chieti, Abruzzi, Italy
PK

Pieter Kamphuisen

Professor of Vascular Medicine
Department of Internal Medicine, Tergooi MC, Hilversum, The Netherlands
Hilversum, Noord-Holland, Netherlands
LP

Lars Pedersen

Prof, MSc, PhD
Department of Clinical Epidemiology, Aarhus University Hospital and Aarhus University, Aarhus, Denmark
Aarhus, Midtjylland, Denmark
Nick van Es, MD PhD

Internist-vascular medicine
Department of Vascular Medicine, Amsterdam University Medical Centers, Amsterdam, the Netherlands
Amsterdam, Noord-Holland, Netherlands
HS

Henrik Toft Sørensen

MD, PhD, prof
Department of Clinical Epidemiology, Aarhus University Hospital and Aarhus University, Aarhus, Denmark
Aarhus, Hovedstaden, Denmark

Background: Guidelines suggest using risk assessment tools to identify ambulatory cancer patients at high risk of venous thromboembolism (VTE). A recently derived risk-assessment score for cancer-associated thrombosis (CAT) appears to perform better than the Khorana score (Li et al. JCO 2023).

Aims: To externally validate the new score in a diverse population of patients with cancer.

Methods: We used data from population-based healthcare registries and electronic medical records from the Central Denmark Region to calculate the Khorana and new CAT risk scores in patients with a first-time cancer diagnosis initiating systemic cancer therapy. Patients were followed for 6 months after start of therapy. The study outcome was VTE, identified through hospital discharge diagnoses. The cumulative incidence was calculated with death as competing event. The scores' discrimination was assessed using c-statistics. Sensitivity and specificity were calculated for the recommended positivity threshold.

Results: Between 2012 and 2020, 12,471 patients with cancer were included. The most frequent cancer types were breast (29%), lung (19%), and colorectal (16%) cancers (Table 1). During 6-month follow-up, 416 (3.3%) patients developed VTE. The c-statistic was 0.71 (95-CI: 0.68–0.74) for the new CAT score and 0.66 (95%-CI: 0.63–0.70) for the Khorana score. Cumulative VTE incidence was 5.0% in 6,175 patients classified as high-risk based on the new CAT score, compared with 1.7% in 6,296 patients classified as low-risk according to this new score (odds ratio, 3.05; 95%-CI: 2.44–3.81)(Figure 1). The sensitivity and specificity were 0.74 and 0.51, respectively for the new CAT score and 0.53 and 0.65 for the Khorana score.

Conclusion(s): In this large cohort study, the new CAT score had discriminatory ability similar to that reported in its derivation study. Its c-statistic was numerically higher than that of the Khorana score. Our findings support use of the new CAT score to identify ambulatory patients with cancer at high risk of VTE.