D-Dimer Dynamics as a Prognostic and Monitoring Biomarker in Triple-Negative and Metastatic Breast Cancer: A Narrative Review.

Abstract

Background: Triple-negative breast cancer (TNBC) and metastatic breast cancer (MBC) remain clinically challenging because of aggressive biology, therapeutic resistance, metastatic dissemination, and substantial heterogeneity. D-dimer, a fibrin-degradation product, may capture systemic coagulation and fibrinolytic activation associated with tumour progression and cancer-associated thrombosis.

Objective: This narrative review critically examines D-dimer dynamics as a complementary biomarker for prognostic stratification, treatment monitoring, thrombotic risk assessment, and personalized care in TNBC and MBC.

Results: Evidence linking D-dimer with tumour burden, metastasis, survival, inflammation, endothelial activation, platelet-tumour interactions, and venous thromboembolism is synthesized. Particular emphasis is placed on longitudinal trajectories, including declining, stable, persistently elevated, and progressively increasing D-dimer patterns, and their potential interpretation alongside imaging, clinical status, inflammatory markers, circulating tumour DNA, and treatment exposure. Major limitations include assay heterogeneity, differences between fibrinogen-equivalent units and D-dimer units, variable reference ranges and cut-offs, and confounding by age, infection, surgery, renal or hepatic dysfunction, immobility, prior thrombosis, and anticancer treatment. Most available evidence remains observational and therefore establishes association rather than causality or proven clinical utility.

Conclusion: D-dimer dynamics represent a promising, accessible component of multimodal precision oncology, but should not independently diagnose progression, select anticancer therapy, or determine anticoagulation. Prospective multicentre studies are needed to standardize assays, validate trajectory-based thresholds, integrate D-dimer with multi-omics and artificial intelligence, and determine whether D-dimer-guided monitoring improves outcomes, particularly in resource-constrained settings and diverse African oncology populations globally appropriately.