DETECTION OF BLADDER-TUMORS BY IMMUNOSTAINING OF THE LEWIS-X ANTIGEN IN CELLS FROM VOIDED URINE

Objectives. A study was made to determine the sensitivity and specific ity of immunostaining of the Lewis X antigen in exfoliated urothelial cells from voided urine, for the detection and surveillance of bladder tumors. Methods. Three consecutive voided urine specimens were obtain ed from 101 patients, 78 of whom were under surveillance because of a history of bladder tumors, and 23 were being evaluated because of hema turia or irritative urinary symptoms. Indirect immunoperoxidase staini ng of two urine samples was done on cytocentrifuge slides, using the P 12 monoclorial antibody against the Lewis X antigen. The diagnosis of the presence of a urothelial tumor was made if more than 5% of the cel ls showed a typical red-brown staining. Cytopathologic examination of the third urine specimen was done according to Papanicolaou. Each pati ent underwent cystoscopy, and biopsies were obtained whenever there wa s endoscopic evidence of bladder tumors or carcinoma in situ. Results. Cystoscopy and biopsies revealed transitional cell carcinoma in 32 pa tients, whereas 69 patients had no evidence of bladder tumors. Immunoc ytology of one urine sample showed true-positive results in 26 of the 32 patients with bladder tumors, corresponding to a sensitivity of 81. 25%. When two samples were examined, a sensitivity of 97% and a specif icity of 85.5% were obtained. When the results of cytology and immunoc ytology were combined, sensitivity reached 100%. High-grade and low-gr ade transitional cell tumors were detected with equal efficiency. Conc lusions. The use of P12 monoclonal antibody for evaluation of Lewis X reactivity in cytologic preparations from multiple voided urine specim ens can improve the sensitivity of noninvasive detection of bladder ca ncer. The technique may ultimately replace cystoscopy in monitoring th erapeutic response and tumor recurrence.