Detection of transitional cell carcinoma in bladder by intravesical injection of monoclonal antibodies

Monoclonal antibodies produced against tumor associated antigens of human bladder transitional cell carcinoma have proved to be useful in detecting malignant cells in tumor sections and bladder washings. The present study evaluated the capacity of one such antibody G4 to identify sites of malignancy when introduced into the lumen of intact bladders immediately after cystectomy. An ex vivo immunoperoxidase staining (IPS) method was applied to four cystectomy specimens--three with solitary invasive transitional cell carcinomas (TCC) and one with carcinoma in situ (CIS) using monoclonal antibody G4 injected intravesically immediately after cystectomy. The tumor sites, normal appearing mucosa and other exposed and non exposed tissues from the same patient were examined for G4 binding. In all cases preferential intravesical binding of G4 antibody to the tumor size was demonstrated without binding to the normal mucosa except in one case. This study showed that monoclonal antibody injected intravesically can be focused on the tumor site and indicates that G4 and other antibodies may be useful intravesically for selectively assessing field changes associated with malignancies or as specific therapeutic agents.