The PROTECHT and 5 single nucleotide polymorphism (SNP) scores were no more effective in predicting the risk of venous thromboembolism (VTE) in cancer patients than the Khorana score. These results were published in the Journal of Thrombosis and Haemostasias.
The data were assessed from the Center for Personalized Cancer Treatment study, a Dutch multicenter prospective study. The patients included were retrospectively assessed by the Khorana, PROTECHT and 5-SNP risk scores. Khorana and PROTECHT scores are calculated based on risk based on 5 and 7 clinical features, respectively, and 5-SNP score is calculated based on the presence of 5 risk loci. The predicted risk scores for VTE were compared to the incidence of radiologically confirmed VTE.
Patients (N = 2729) had a median age of 63 years (interquartile range [IQR], 55-70) years, 49.2% were female and the most common types of cancer were breast (17.5%), melanoma (12.3%), colorectal (11.4%) and the lung (11.1%).
At 6 months, 5.9% of patients developed VTE for an overall incidence rate of 6.4% (95% CI, 5.5% -7.4%). Of the patients who developed VTE, 51.9% had pulmonary embolism, 25.0% had deep vein thrombosis of the lower limbs, and 23.1% had another type of VTE. The events were symptomatic (53%) and 41% were detected accidentally.
The discriminant performance of Khorana was 0.57 (95% CI, 0.55-0.60), PROTECHT was 0.60 (95% CI, 0.57-0.62) and the 5-SNP was 0.54 (95% CI, 0.51-0.57).
The proportion of patients classified as high risk by Khorana was 9.6% and 90.4% were determined to be low risk. At 6 months, the cumulative incidence of VTE was 11.8% (95% CI 7.8% to 16.7%) among the high-risk cohorts and 6.1% (95% CI , 5.1% to 7.2%) among low risk cohorts; indicating a sensitivity of 16.6% and a specificity of 90.8%.
For PROTECHT, 16.8% were classified as high risk and 83.2% as low risk. The cumulative incidence rates of VTE among the high and low risk groups were 11.5% (95% CI, 8.5% to 15.0%) and 5.6% (95% CI, 4.6% to 6.7%), corresponding respectively to a sensitivity of 49.6% and specificity of 67.0%.
Using the 5-SNP criteria, 9.5% were classified as high risk and 90.5% as low risk. The cumulative incidence rates of VTE were 10.3% (95% CI, 6.3% to 15.4%) for those at high risk and 6.1% (95% CI, 5 , 1% to 7.4%) for those at low risk. Overall, this risk scoring method had a sensitivity of 28.2% and a specificity of 76.0%.
This study may have been limited by the 5% of patients lost to follow-up during the study.
These data indicated that the 5-SNP score was not as good at predicting VTE in cancer patients as the validated Khorana score. Moreover, PROTECHT risk score was not higher than that of Khorana, with similar performance. Overall, more study is needed to identify factors that are more effective in predicting the risk of VTE.
Disclosure: Several authors have declared affiliations with the industry. Please refer to the original article for a full list of disclosures.
Guman NAM, van Geffecn RJ, Mulder FI, et al. Assessment of Khorana, PROTECHT and 5-SNP scores for the prediction of venous thromboembolism in cancer patients. J Thromb Haemost. Published online 19 Aug 2021 doi: 10.1111 / jth.15503