[1089] GATA3 Expression in Matched Paired Primary and Metastatic Urothelial Carcinomas

Lei Zhao, Gladell P Paner, Jerome B Taxy, Tatjana Antic, Maria Tretiakova. University of Chicago, Chicago, IL

Background: GATA3 has been recognized as a promising marker for primary urothelial carcinoma (UC), consistently showing higher expression levels than urothelial markers thrombomodulin and uroplakin III. However, the preservation of GATA3 expression in metastatic UC when compared to a primary site has not been investigated. The aim of this study was to evaluate the sensitivity of GATA3 as a diagnostic marker for metastatic UC by comparing expression of GATA3 in matched primary and metastatic conventional urothelial carcinomas, and to correlate it with well established UC-associated markers CK7 and p63.
Design: Tissue microarrays including 68 matched primary and metastatic UCs of conventional morphology were constructed, with normal urothelium as a control. Each case was represented by five 1 mm cores: 2 duplicate cores from the primary tumor and 2-3 cores from lymph node metastases. Immunohistochemical staining for GATA3, CK7 and p63 was performed with appropriate controls.
Results: Strong nuclear reactivity with GATA3 was observed in normal urothelium, 88.2% of primary UC and 91.2% of metastatic UC, showing similar sensitivity when compared to CK7 and significantly higher sensitivity when compared to p63 (p<0.05).

Comparison of GATA3, CK7 and p63 expression in matched primary and metastatic UC
MarkerPrimary UCMetastatic UC
GATA388.2% (60/68)91.2% (62/68)
CK786.8% (59/68)88.2% (60/68)
p6373.5% (50/68)76.5% (52/68)


From 68 paired primary-metastases cases, GATA3 demonstrated persistent positive staining in 60 cases. No cases demonstrated loss of GATA3 expression in metastatic sites. Two cases were positive for GATA3 in metastatic UC only. CK7 was lost in two and gained in three metastatic UCs. P63 was lost in one and gained in three metastatic UCs.
Conclusions: GATA3 demonstrates high sensitivity for urothelial carcinoma, which is comparable to CK7 and superior to p63. Matched primary-metastasis pairing study demonstrates preservation of GATA3 expression in all cases. To our knowledge this is the first study showing that GATA3 nuclear positivity is maintained at the same level in metastatic sites of conventional UC, thus making GATA3 a valuable marker for metastatic carcinomas of unknown primary origin.
Category: Genitourinary (including renal tumors)

Tuesday, March 5, 2013 9:30 AM

Poster Session III # 103, Tuesday Morning

 

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