Development and External Validation of a Postoperative Risk Score for Venous Thromboembolism in Epithelial Ovarian...

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is a major complication in women with epithelial ovarian cancer (EOC). We aimed to develop and externally validate an early postoperative risk score to identify EOC patients at increased risk of VTE after debulking surgery. We retrospectively analyzed a development cohort (N = 358) to derive and internally validate a prediction model and an independent external cohort (N = 158) for external validation. Candidate clinical and laboratory variables were evaluated using least absolute shrinkage and selection operator (LASSO) and multivariable logistic regression. The final model was presented as a nomogram and converted into an integer-based scoring system. Postoperative VTE within 30 days of surgery occurred in 12.01% of patients in the development cohort. Age, body mass index (BMI), preoperative international normalized ratio (INR), preoperative aspartate aminotransferase (AST), postoperative C-reactive protein (CRP), and postoperative platelet count (PLT) were retained as predictors. The score incorporated age, BMI, INR, AST, CRP, and postoperative platelet count. Using a cutoff of 5 points, discrimination was high in the training and internal validation cohorts and acceptable in external validation (AUC 0.990 [95% CI 0.981-1.000], 0.934 [0.874-0.995], and 0.791 [0.653-0.929], respectively). In external validation, discrimination was comparable to the G-Caprini score (AUC 0.759 [0.627-0.892]) with overlapping confidence intervals. Because the proposed score incorporates postoperative biomarkers, it is intended for early postoperative risk reassessment to support targeted surveillance and individualized post-surgical prevention strategies, rather than preoperative prophylaxis decision-making.