Biologic behavior of and p53 overexpression in multifocal renal cell carcinoma of clear cell type - An immunohistochemical study correlating grading,staging, and proliferation markers

BACKGROUND, In the treatment of small renal cell carcinoma (RCC), there is controversy between radical and nephron-sparing surgical treatment because of the risk of tumor multifocality. The biologic behavior of multifocal RCC compared with that of unifocal RCC is not well investigated, and the relev ance of p53 and the proliferation markers MIB-1 and proliferating cell nucl ear antigen (PCNA) to multifocal RCC is not vet established. METHODS. In this study, p53 protein overexpression was investigated immunoh istochemically in 27 multifocal and GS unifocal clear cell RCCs using a mon oclonal antibody (DO-1). The nuclear expression of p53 was compared with th e expression of PCNA and MIB-1 (Ki-67 antigen) and other prognostic factors , including grade and stage. RESULTS. Thirty-three RCCs (35.9%) had p53 positive nuclear staining. MIB-1 positivity was significantly higher in p53 positive tumors than in p53 neg ative turners. PCNA positivity was nor different in p53 positive tumors com pared with p53 negative tumors. Proliferation marker expression was not ass ociated with tumor focality. p53 overexpression was more often found in uni focal tumors than in multifocal tumors. Intracellular accumulation of the p 53 protein was related to tumor grade bur not to the T classification of tu mor stage. In addition, lymph node involvement was significantly associated with p53 overexpression in tumors of the kidney. Focality did not influenc e progression free survival. CONCLUSIONS. This study demonstrated that there is no difference in the pro liferative activity or biologic behavior of multifocal and unifocal tumors. (C) 1999 American Cancer Society.