[355] GATA3 Expression in Cytology Samples of Metastatic Breast Versus Gynecological Carcinoma and Comparison with GCDFP15 and Mammaglobin

Georgios Deftereos, Uma Krishnamurti, Jan F Silverman. Allegheny General Hospital, Pittsburgh, PA

Background: GATA3 (GATA binding protein 3) is a transcription factor reported to play a role in cell proliferation and differentiation. It has been shown to be highly expressed in the Luminal A subtype of breast cancer. In contrast to the data available for GCDFP15 and mammaglobin, there is lack of reports on the utility of GATA3 in distinguishing metastatic breast versus metastatic gynecological cancer in cytology specimens.
Design: 29 cytology cases comprised of 19 effusions and 10 fine-needle aspirations were selected (17 cases of metastatic breast cancer, 9 cases of metastatic ovarian cancer and 3 cases of metastatic endometrial cancer). All cases had surgical resections on which final diagnosis had been made. Immunostaining was performed for GATA3, GCDFP15 and Mammaglobin. For GATA-3 staining intensity was scored as 1+, 2+ and 3+ and an H-score was calculated by multiplying the intensity and the percentage of neoplastic cells that stained. GATA3 expression was compared with that of GCDFP15 and mammaglobin.
Results: All 17 (100%) of metastatic breast cancer cases, including one ER-negative case, stained with GATA3. This was significantly higher than with GCDFP15 (4/17, 23.53%; p<0.0001) and mammaglobin (6/17, 35.29%, p<0.0001). The mean H-score for GATA3 was 224. None of the metastatic endometrial or ovarian carcinomas were positive for GATA3. GCDFP15 also showed no staining in metastatic endometrial and ovarian carcinomas, while mammaglobin showed immunoreactive cells in 1/ 9 (11.11%) metastatic ovarian carcinomas.
Conclusions: 1. GATA3 is significantly more sensitive than GCDFP15 and mammaglobin in the detection of metastatic breast cancer in cytology specimens. 2. Staining with GATA3 appears to be specific for a breast primary compared to metastatic carcinomas of gynecologic origin. Thus, in metastases of unknown primary particularly those that are estrogen receptor positive, GATA3 can be valuable in determining the breast origin and excluding a gynecologic primary.
Category: Cytopathology

Monday, March 4, 2013 1:00 PM

Poster Session II # 105, Monday Afternoon

 

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