Association between D-dimer difference and risk of postoperative venous thromboembolism in endometrial cancer: a retrospective cohort study

OBJECTIVE: To investigate the association between D-dimer level changes and venous thromboembolism (VTE) risk in endometrial cancer patients undergoing surgery. METHODS: This retrospective cohort study included 307 endometrial cancer patients who underwent surgical treatment at Fujian Maternity and Child Health Hospital between January 2022 and December 2024, with follow-up to December 2025. D-dimer change was the exposure variable and VTE occurrence the outcome. Multivariable logistic regression assessed independent effects after adjusting for 17 covariates, including age, body mass index, FIGO stage, and comorbidities. Threshold effect and stratified analyses were conducted. RESULTS: Each one-unit increase in D-dimer change was significantly associated with higher VTE risk (adjusted OR = 1.202; 95% CI: 1.076-1.342; P = 0.001). Nonlinear testing revealed a significant threshold effect (P < 0.001) at 3.78: below this threshold, VTE risk increased sharply (OR = 7.761; 95% CI: 4.286-14.051); above it, risk declined (OR = 0.643; 95% CI: 0.526-0.785). Mediation analysis showed anticoagulant therapy, infection, and caprinin had negligible mediating effects (proportion < 0.2%; P > 0.86). CONCLUSION: D-dimer level changes exhibit a nonlinear association with postoperative VTE risk, characterized by a distinct threshold effect. These hypothesis-generating findings suggest that monitoring D-dimer trajectories rather than absolute values may offer a novel dimension for perioperative VTE risk stratification, warranting prospective validation in multicenter cohorts before clinical application.