Intravesical administration of EGF- dextran conjugates in patients with superficial bladder cancer.

Abstract

Overexpression of the epidermal growth factor receptor (EGFR) has been reported in bladder cancer and is a potential target for therapy with radionuclides. In this study, we investigated the binding of EGF-dextran-(99m)Tc to the EGFR. The aim of this study was to determine if intravesically administered EGF-dextran conjungate selectively accumulated in the tumor tissue and to correlate the uptake to tumor characteristics. Eight patients received the conjugate intravesically for about 30 min followed by bladder irrigation and then transurethral resection. Radioactivity of the biopsy specimens from normal urothelium and tumor areas was measured in a gamma counter. Five patients received EGF-dextran-(99m)Tc, three received dextran-(99m)Tc and one received only (99m)Tc. The 5 patients who received the complete conjugate had a mean ratio of radioactivity between tumor and normal urothelium of 664:1 (range: 2.4-1,710). The dextran-(99m)Tc showed a slightly increased ratio and (99m)Tc did not bind at all. The results are encouraging and further studies are warranted to investigate if EGF-dextran could be effective as intravesical therapy, either conjugated with cystostatic drugs or labeled with suitable radionuclides.