INTRAVESICAL ADMINISTRATION OF TUMOR-ASSOCIATED MONOCLONAL-ANTIBODY AUA1 IN TRANSITIONAL-CELL CARCINOMA OF THE BLADDER - A STUDY OF BIODISTRIBUTION

Forty-five patients known or suspected to have transitional cell carci noma of the urinary bladder underwent intravesical administration of e ither AUA1 tumor-associated monoclonal antibody or 11.4.1. nonspecific monoclonal antibody. Antibodies were radiolabeled with iodine-131, di luted in 50 ml normal saline and remained in the bladder for up to 1 h . During cystoscopy or transurethral resection of the tumor, tissue sa mples were taken from normal and malignant areas and were counted for radioactivity in a gamma counter. Blood samples were also measured for radioactivity. Mean uptake of AUA1 at 2, 20, 40 and 60 h after admini stration (expressed as 10(3) x percentage of injected dose/gram of tis sue) was: 1.77 +/- 3.2, 1.28 +/- 1.67, 0.72 +/- 0.94 and 0, respective ly in the tumor and 0.79 +/- 0.8 3, 0.14 +/- 0.34, 0.033 +/- 0.06 and 0 in normal tissue. Mean uptake of 11.4. 1 at 2 and 20 h was: 0.47 +/- 0.42 and 0.018 +/- 0.015, respectively, in tumor and 0.2 +/- 0.19 and 0.013 +/- 0.002 in normal samples. No remarkable radioactivity was fo und in blood samples. Conventional and immunoperoxidase staining were also performed. Mean uptake of AUA1 by the tumor increased as the degr ee of tumor differentiation decreased. Our findings indicate that intr avesical administration of AUA1 results in selective immunolocalizatio n of AUA1 in intermediate and high-grade transitional cell carcinoma. This may allow the development of a new method for bladder carcinoma t reatment or prophylaxis against recurrence.