OVEREXPRESSION OF c-erbB-2 AND p53 ONCOPROTEIN IN RENAL PELVIC AND URETERAL CARCINOMAS WITH REFERENCE TO THE EXPRESSION OF Ki-67 ANTIGEN AS A PROLIFERATION MARKER

Abstract

(Purpose) We determine the significance of c-erbB-2 and p53 gene in the progression of renal pelvic and ureteral carcinomas.
(Methods) Overexpression of c-erbB-2 and p53 oncoprotein was investigated using immunohistochemical staining with reference to pathological features. The expression of Ki-67 antigen was also studied as a proliferation marker.
(Results) Forty-seven cases were examined, and the overexpression of c-erbB-2 oncoprotein was revealed in 25 (53%) cases. It was not related both tumor grade (G) and tumor stage (pT).
The overexpression of p53 oncoprotein was revealed in 29 (62%) cases. There were 13 p53 positive cases in 27 low grade (G1, G2) tumors, and 16 in 20 high grade (G3) tumors. There were also 8 p53 positive cases in 21 low stage (pTa, pT1) tumors, and 21 in 26 high stage (pT2-4) tumors. Thus, p53 oncoprotein was more frequently overexpressed in high grade tumors (p<0.05) and in high stage tumors (p<0.01).
Ki-67 labelling index (LI, mean±SD) was 10.7±8.9 in low grade tumors and 26.3±12.5 in high grade tumors. It was also 9.0±8.1 in low stage tumors and 24.0±12.4 in high stage tumors. Thus, Ki-67 LI was higher in high grade tumors (p<0.01) and in high stage tumors (p<0.01). The c-erbB-2 status and Ki-67 LI were not correlated, while the LI of p53 positive cases (21.7±13.6) was significantly higher (p<0.01) than it of p53 negative cases (10.3±8.5). The difference of LI between p53 positive cases and p53 negative cases was significant (p<0.05) in lowgrade tumors, but in high grade tumors LI was higher than it of low grade tumors independentlyof p53 expression.
(Conclusion) p53 but not c-erbB-2 was considered to be associated with rapid tumor progression in renal pelvic and ureteral carcinoma and play an important role in its progression especially in low grade tumors.