Simple, Effective and Validated. VTE CASE Risk Assessment Score for Venous Thromboembolism in Metastatic Germ Cell Tumour Patients Before First-Line Chemotherapy

Background: Venous thromboembolism (VTE) may jeopardise excellent treatment results of germ cell tumours (GCT). We previously constructed a VTE risk score for GCT patients qualified for first-line chemotherapy (CTH), including vein compression, clinical stage (CS) and haemoglobin concentration.

Aim: Validating our score in a separate cohort and establishing the cut-off point for the score. Re-assessing the numerical score in the training cohort.

Materials and methods: We retrospectively analysed a new cohort of GCT patients staged IS-IIIC. Area under the curve of receiver-operating characteristic (AUC-ROC) was calculated for the developed score, Khorana Risk Score (KRS) and Padua Prediction Score (PPS). AUC-ROC of the integer score was calculated for the training cohort. Cut-off point was established by Youden's and Liu's indices.

Results: Among 336 eligible patients in the validation cohort, VTE occurred in 41 (12.2%). AUC-ROC for our score, KRS and PPS were 0.818 (95% confidence interval (CI): 0.746-0.891), 0.608 (0.529-0.688) and 0.634 (0.547-0.720), respectively, p < 0.001. The optimal cut-off point for a low/high risk was 6 (≤ 6 vs. ≥ 7). In the training cohort, 369 patients had complete data on vein compression. AUC-ROC for our score, KRS and PPS were 0.819 (95% CI: 0.758-0.879), 0.710 (0.637-0.782) and 0.725 (0.651-0.800), p ≤ 0.001 and 0.015, respectively. Positive and negative predictive values were 30.8% and 96.5%, respectively.

Conclusions: Our VTE risk score is a handy tool for GCT patients before first-line CTH for metastatic disease. Outperforming KRS and PPS, it has a good discriminatory value, especially for identifying low-risk patients.