[1023] GATA3, p63 and S100P: An IHC Comparison Analysis in Bladder Cancer

David Tacha, Ryan Bremer, Charlie Yu, Liang Chen. Biocare Medical, Concord, CA; Indiana University School of Medicine, Indianapolis, IN

Background: More than 90% of bladder cancers are urothelial (transitional) cell carcinomas (TCC), which originate in the mucous layer of surface cells of the bladder lining (transitional epithelial cells). Establishing urothelial origin of the tumor is critically important, especially when prostate cancer is also in differential diagnosis. Several studies have shown p63 to be a sensitive marker for bladder cancers and negative in prostate and kidney cancers; however, only limited studies of GATA3 and S100P have been reported in bladder, prostate and kidney cancers. The aim of this study is to examine immunohistochemical staining characteristics of GATA3, p63 and S100P antibodies on bladder TCC, and compare staining expression of GATA3 and S100P on prostate and kidney cancers.
Design: Formalin-fixed, paraffin-embedded TMA's of bladder cancers were constructed in-house and purchased commercially, and processed in the usual manner for IHC analysis. All sections were retrieved in a modified citrate buffer, in a pressure cooker at 125°C. Mouse monoclonal antibodies GATA3 and p63, and rabbit polyclonal antibody S100P, were individually optimized using a 30 minute incubation. Detection was performed using a micro-polymer and visualization with DAB chromogen.
Results: The results of GATA3, p63 and S100P in TCC are summarized in Table 1.

Table 1: Transitional Cell Carcinoma: All grades

Antibody	Cases	Positive	(+) %	Negative	(-) %
GATA3	59	54	92%	5	8%
p63	59	53	90%	6	10%
S100P	59	55	93%	4	7%

Positive staining of each antobody, according to histologic grade is summarized in Table 2.

Table 2: Staining of GATA3, p63 and S100P in TCC according to histologic grade

Grade 1-3	GATA3	p63	S100P
Grade 1 (11 cases)	10 (91%)	11 (100%)	11 (100%)
Grade 2 (37 cases)	33 (89.2%)	32 (86.5%)	33 (89.2%)
Grade 3 (11 cases)	10 (90.1%)	9 (81.2%)	9 (81.2%)

GATA3 was 100% negative in prostate (n=68) and kidney cancers (n=69) and S100P was 100% negative in kidney cancer and 98.6% negative in prostate cancer.
Conclusions: GATA3, p63 and S100P are highly sensitive and specific biomarkers for urothelial carcinoma. The combination of this 3 biomarker panel may be employed to establish urotheluial origin and will aid in cases of tumor of unknown origin.
Category: Genitourinary (including renal tumors)

Tuesday, March 20, 2012 1:00 PM

Poster Session IV # 83, Tuesday Afternoon