In 1998 WHO/ISUP consensus meeting, stage pTa urothelial cell neoplasms of the bladder were classified under the term “non-invasive papillary urothelial neoplasms” and four histomorphologic subgroups were defined. This study evaluate whether p53 and Ki-67 overexpression in these subgroups may be of value in estimating recurrences and prognosis.
Materials and Methods: A retrospective review was made of 50 cases who were diagnosed papilloma, grade-II (Mostofi) and stage pTa urothelial cell carcinoma between 1995-99 in Taksim State Hospital. All cases were classified into four subgroups according to the concensus. Samples were stained immunohistochemically for p53 and Ki-67 and correlation was sought between overexpression of p53 and Ki-67 and prognosis.
Results: 95% of the bladder carcinomas diagnosed in our laboratory were of ürothelial cell origin and 32% of these were in stage pTa and papilloma grade I-II (Mostofi). 15% of the cases were urothelial papilloma (UP), 33% papillary urothelial neoplasm with low malignant potential (PUN-LMP), 29% low-grade papillary urothelial carcinoma (LG-PUC) and 23% high-grade papillary urothelial carcinoma (HG-PUC). Mean expression levels of p53 and Ki-67 were 0.03 and 0.0380 in urothelial papilloma, 0.0660and 0.080 in papillary urothelial neoplasm with low malignant potential, 0.1999 and 0.1969 in low-grade and 0.3517 and 0.3010 in high-grade papillary urothelial carcinoma, respectively.
Conclusion: The study results were consistent with WHO/ISUP concensus classification with respect to recurrence and progression of papillary urothelial neoplasms, with p53 and Ki-67 overexpression levels being compatible with the diagnosis of the subgroups.