[794] Role of Tissue Biomarker Expression in the Prognosis of Clear Cell Renal Cell Carcinoma

MJ Kim, WJ Sung, DC Park. Yeungnam University Hospital, Daegu, Republic of Korea

Background: Conventional, or clear cell, renal cell carcinoma is the most common subtype of renal cell carcinoma, characterized by its diverse clinical course. Identification of clinicopathologic parameters and specific molecular markers predicting clinical outcome has become an important and controversial issue. The aim of this study is to analyze the expression of several biomarkers in clear cell renal cell carcinoma and to assess their prognostic significance. We also tried to correlate these molecular markers to clinical and pathologic indices, such as age, sex, tumor size, TNM stage, and Fuhrman nuclear grade.
Design: The study is composed of 111 clear cell renal cell carcinoma obtained from nephrectomy specimen at Yeungnam University Hospital between 2000 and 2007. The expression of biomarkers including EGFR, erbB2/neu, KIT, PDGFR-, TGF- receptor type II, galectin-3, PTEN and Ki-67 was immunohistochemically performed on tissue microarray slides contained a tissue core from normal renal tissue and tumor. Stained slides on each marker were evaluated for protein expression using 4-level scale (o = none, 1 = low, 2 = moderate, 3 = high). Level 2 and 3 was considered as positivity.
Results: Tumor stages were pT1 89 (80%), pT2 11 (10%), pT3 10 (9%), pT4 1(1%). Fuhrman nuclear grade 1/ 2/ 3/ 4 was 10 (9%)/ 43 (39%)/43/15 (13%), respectively. There was no significant difference between clinicopathologic features and patients' survival. 50 out of 111 cases of clear cell renal cell carcinoma (45.0%) showed overexpression of EGFR, while 74 cases of PTEN (76.6%), 89 of galectin-3 (80.9%), and 76 of TGF- receptor type II (68.5%) revealed none to low expression. EGFR overexpression was significantly associated with higher nuclear grade (p = 0.001), larger tumor size (p = 0.016), and higher Ki-67 labeling index (p = 0.034). None/low TGF- receptor type II expression was significantly correlated with decreased overall survival (p = 0.023) and higher nuclear grade (p = 0.001), and low PTEN expression (p = 0.001). Fuhrman nuclear grade was closely related to overexpression of EGFR, none/low TGF- receptor type II expression, and loss of galectin-3 protein (p = 0.014).
Conclusions: This study showed that overexpression of EGFR and none to low expression of TGF- receptor type II, and loss of galectin-3 are not only linked to poor clinical outcome but also well correlated with higher nuclear grade in clear cell renal cell carcinoma.
Category: Genitourinary (including renal tumors)

Tuesday, March 10, 2009 9:30 AM

Poster Session III # 81, Tuesday Morning