[170] Discordance of Estrogen Receptor (ER), Progesterone Receptor (PR) and Her-2/Neu Expression between Primary Breast Carcinoma and Brain Metastasis.

Shveta Hooda, Gloria Carter, Mamatha Chivukula. UPMC, Pittsburgh, PA

Background: About a third of invasive breast carcinomas metastasize to brain. Breast cancer patients who developed brain metastasis had higher proportions of triple-negative and HER2+/ER- tumor expression. There is paucity of information on the discordance of Estrogen Receptor(ER), Progesterone Receptor (PR) and Her-2/neu status between primary and metastatic breast carcinoma although this might affect the systemic therapy of the patient's metastatic disease. The aim of our study is to analyze the ER, PR and Her2/neu expression of primary breast carcinoma that metastasize to brain.
Design: We performed a retrospective analysis of 20 patients with breast carcinoma with documented brain metastasis. We searched the laboratory information system (LIS) (Copath plus) for the ER, PR and Her2/neu data on these patients.
Results: Only the cases with paired data available on atleast one of the markers were included in the study. We found no discordance in ER staining between the primary and metastases. The discordance rate for PR was 22% and for HER2/neu was 7%. Out of the 2 cases that showed discordance in PR staining, 1 case lost PR and the other gained PR in metastases. We found Her2/neu discordance in only 1 case which showed positivity in the metastases.

Discordance of primary breast carcinoma and brain metastasis
 Concordant casesDiscordant cases
ER (n=11)11 (100%)0
PR (n=9)7 (78%)2 (22%)
Her2/neu (n=14)13 (93%)1 (7%)

Conclusions: Absence of discordance for ER is in contrast with some of the previous studies. This might be related to the fact that only brain metastases cases were included in our study while the previous studies have included cases from all metastatic sites. Discordance in PR and HER 2 might reflect the heterogeneity that exists for these receptors. Due to the minor discordances in PR and Her2/neu, we suggest that all the receptors be repeated on the metastatic breast cancer tissue specimens.
Category: Breast

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 47, Tuesday Morning


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