DOES P53 IMMUNOSTAINING IMPROVE DIAGNOSTIC-ACCURACY IN URINE CYTOLOGY

The frequent change of the transitional cell carcinoma of the urinary tract accounts for the fact that cytological abnormalities in urinary specimens are often not sufficient to enable a definitive diagnosis of malignancy. The purpose of this work was to evaluate the possible use of p53 protein in increasing the diagnostic accuracy of urinary cytol ogy. The expression of p53 was investigated by immunocytochemistry in two groups of urinary specimens, one cytologically positive and the ot her cytologically negative for cancer. Immunostaining was carried our using a monoclonal antibody to p53. In the positive group, in which bl adder cancer was confirmed by cystoscopy and biopsy (31 cases), positi ve reaction for p53 was found in 55% of the cases (17 cases). In the n egative group (92 cases), presence of cancer was histologically ascert ained in 64 cases and in this group 15 cases (23.4%) showed positive p 53 staining. In the remaining 28 cases of this group, where TCC was no t present, 7 cases showed p53 positivity in non-neoplastic urothelial cells. This result shows that, while immunocytochemical detection of p 53 in urinary specimens may be used for prognostic evaluation of patie nts with bladder cancel, it does not contribute to the diagnostic accu racy in cases with morphologically inconclusive or negative cytology. The sensitivity and specificity of the method in detecting bladder car cinoma were 23.5 and 75%, respectively. (C) 1997 Wiley-Liss, Inc.