Unveiling the diagnostic enigma of D‐dimer testing in cancer patients: Current evidence and areas of application

Abstract Background Cancer is a well‐known risk factor for venous thromboembolism (VTE). A combined strategy of D‐dimer testing and clinical pre‐test probability is usually used to exclude VTE. However, its effectiveness is diminished in cancer patients due to reduced specificity, ultimately leading to a decreased clinical utility. This review article seeks to provide a comprehensive summary of how to interpret D‐dimer testing in cancer patients. Methods In accordance with PRISMA standards, literature pertaining to the diagnostic and prognostic significance of D‐dimer testing in cancer patients was carefully chosen from reputable sources such as PubMed and the Cochrane databases. Results D‐dimers have not only a diagnostic value in ruling out VTE but can also serve as an aid for rule‐in if their values exceed 10‐times the upper limit of normal. This threshold allows a diagnosis of VTE in cancer patients with a positive predictive value of more than 80%. Moreover, elevated D‐dimers carry important prognostic information and are associated with VTE reoccurrence. A gradual increase in risk for all‐cause death suggests that VTE is also an indicator of biologically more aggressive cancer types and advanced cancer stages. Considering the lack of standardization for D‐dimer assays, it is essential for clinicians to carefully consider the variations in assay performance and the specific test characteristics of their institution. Conclusions Standardizing D‐dimer assays and developing modified pretest probability models specifically for cancer patients, along with adjusted cut‐off values for D‐dimer testing, could significantly enhance the accuracy and effectiveness of VTE diagnosis in this population.