D-dimer test and multidetector-row CT as the diagnostic test in suspected venous thromboembolism in colorectal cancer patients with pharmacokinetic modulating chemotherapy (PMC)

Abstract

8118 Background: Colorectal cancer patients with central venous catheter using PMC have a substantial risk of venous thromboembolism (VTE), although we have had clinical success with PMC, whose regimen was designed as a hybrid of lower metronomic (UFT, Taiho Pharmaceutical Co., Tokyo, Japan) and higher shorter plasma 5-FU concentration (cumulative 5-year survival rate of Dukes' C; 95% in PMC versus 67% in non-PMC group, Proc Am Soc Clin Oncol 22: 1175, 2003). To determine the effectiveness and safety of using D-dimer test and multidetector-row CT (MDCT) as the diagnostic test in cancer patients with suspected VTE, a clinical outcome study was performed in PMC patients through outpatient clinic. Methods: Patients asymptomatically underwent D-dimer test before and after the commencement of PMC regimen. MDCT was additionally performed after showing positive D-dimer. When CT results were positive for VTE, anticoagulation was started. Quality inspection for used catheters (6Fr. Anthrone P-U catheter and Cell site port, Toray Medical Co., Tokyo, Japan) of these patients with VTE through measurement of macro property, toluidineblue dyeing test, and scanning electron microscope were carried out. Results: The overall prevalence of VET in PMC patients have been 2.0% (7 of 350 patients) so far. In this study, 55 patients were enrolled who underwent a curative operation for Dukes' B or C colorectal cancer after December 2002, performed PMC as an adjuvant chemotherapy, and followed over 6 months. 17 out of 55 patients showed positive D-dimer test (30.9%). CT identified venous thrombi in 2 patients (3.7%) and mural thrombosis on catheterized veins in 6 patients (10.9%). The catheters of these patients per se didn't show any significant abnormalities. Patients with negative D-dimer test showed no signs and symptoms of VET. No patients died of fatal VET. Conclusions: In colorectal cancer patients who underwent PMC via central venous catheter, D-dimer test can be used safely as the primary screening test to rule out VET. MDCT can be informative in diagnosis for such patients. No significant financial relationships to disclose.