H. Moch et al., P53 BUT NOT ERBB-2 EXPRESSION IS ASSOCIATED WITH RAPID TUMOR PROLIFERATION IN URINARY-BLADDER CANCER, Human pathology, 25(12), 1994, pp. 1346-1351
Tumor proliferation in bladder cancer is associated with tumor behavio
r. To assess the association between Ki-67 labeling index (LI), p53, a
nd c-erbB-2 overexpression, formalin-fixed tissue samples of 160 patie
nts with transitional cell carcinoma (TCC) of the urinary bladder were
studied by immunohistochemistry. Ki-67 LI was strongly associated wit
h tumor stage (P < .0001), tumor grade (P < .0001), and p53 status (P
= .0014) but not with erbB-2 overexpression (P > .2). Ki-67 LT was hig
her in p53-positive tumors (19%) than in p53-negative tumors (14%) whe
n all stages were compared. Ki-67 LI was independent of p53 expression
in pTa tumors (p53-positive, 9%; p53-negative, 11%), showing that p53
overexpression alone is not sufficient to induce rapid tumor cell pro
liferation in pTa tumors. Ki-67 LI also was independent of p53 express
ion in pT2 to pT4 tumors (p53-positive, 20%; p53-negative, 23%), indic
ating that p53 expression is not necessary for rapid tumor cell prolif
eration in advanced stages. However, there was a striking difference i
n Ki-67 LI between p53-positive pT1 tumors (22.0% +/- 8.8 standard dev
iation [SD]; n = 20) and p53-negative pT1 tumors (9.7 +/- 8.3 SD; n =
22; P=.0001). These results suggest that increased proliferation in p5
3-positive pT1 tumors is caused by additional alterations that occur d
uring tumor progression. Copyright (C) 1994 by W.B. Saunders Company