The clinical usefulness of D-dimer testing in cancer patients with suspected deep venous thrombosis.
BACKGROUND
Little is known about the diagnostic value of a D-dimer test in cancer patients with clinically suspected deep venous thrombosis (DVT).


OBJECTIVE
To evaluate the clinical utility of a whole blood rapid D-dimer test (SimpliRED) in cancer patients compared with noncancer patients.


METHODS
In consecutive patients with suspected lower limb DVT, a D-dimer test and ultrasonogram were performed. Cancer status was recorded at presentation. If the D-dimer test and ultrasonogram results were normal, DVT was considered absent. If the D-dimer result was abnormal, ultrasonography was performed again 1 week later. Anticoagulant therapy was only instituted in those patients with an abnormal ultrasonography result. All patients were followed up for 3 months to record subsequent thromboembolic events. The accuracy of the D-dimer test was assessed, and the efficiency and safety of withholding additional ultrasonography in cancer patients with normal results on both D-dimer and ultrasonography was compared with noncancer patients.


RESULTS
A total of 1739 consecutive patients were studied, 217 (12%) of whom had cancer. The negative predictive value of the D-dimer test was 97% in both cancer and noncancer patients. In 63 (29%) of all 217 cancer patients, the D-dimer and ultrasonography results were normal at referral; therefore, the diagnosis of DVT was refuted and anticoagulant treatment was withheld. In these 63 patients, one thromboembolic event occurred during follow-up (1.6%; 95% confidence interval, 0.04%-8.53%).


CONCLUSIONS
The negative predictive value of a whole blood D-dimer test in cancer patients seems as high as in noncancer patients. In a substantial proportion of cancer patients, the diagnosis can likely be refuted at referral, based on normal D-dimer test and ultrasonogram results. Furthermore, it seems safe to withhold anticoagulant therapy in these patients.
ten Wolde
Marije
M
Department of Vascular Medicine, Room F4-138, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands. M.tenwolde@amc.uva.nl
Kraaijenhagen
Roderik A
RA
Prins
Martin H
MH
Büller
Harry R
HR
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000933:Antifibrinolytic Agents / Q000097:blood*; D016022:Case-Control Studies; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013997:Time Factors; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology
D000933:Antifibrinolytic Agents; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D