A New D-dimer Cutoff Value to Improve the Exclusion of Deep Vein Thrombosis in Cancer Patients

Objective: To find a more appropriate alternative to D-dimer cutoff value for the diagnosis of deep veinthrombosis (DVT) in cancer patients.
Methods: A total of 711 cancer patients with symptoms suspicious of DVTwere included in the study. D-dimer levels were assessed using ELISA. All patients were subjected to imagingprocedures.
Results: Among 711 patients with cancer, 466 (65.5%) were females and 245 (34.5%) were males,with an average age of 57.3± 13.23 years. The mean age in the DVT group was significantly higher than in thenon-DVT group (P<0.05). The D-dimer levels of the DVT group were significantly higher than those of thenon-DVT group (P<0.05). The incidence rate of DVT varied significantly according to cancer type (P<0.05).Increasing age and lung cancer were significantly correlated with D-dimer levels (P<0.05), and a one-yearincrease in age was associated with a 14.28 ng/ml increase in the D-dimer value. The optimal cutoff point forD-dimer was found to be 981 ng/ml, with a sensitivity of 86.4%, specificity of 79.4%, and accuracy of 82.6%. Ifthe D-dimer cutoff point was set to 981ng/ml, the specificity would increase from 61.8% to 85.5% without lossof sensitivity in patients aged 40 years or younger. In patients aged more than 40 years, the new cutoff almostdoubled the specificity with slightly reduced sensitivity.
Conclusion: In cancer patients, a new cutoff value of981 ng/ml effectively improved the exclusion of DVT, especially for patients aged more than 40 years.