[134] The Concordance of Estrogen and Progesterone Receptor Status (ER-PR), and Her-2/Neu Expression in DCIS Coexistent with Micro-Invasive and Invasive Carcinoma

Q Ahmed, R Ali-Fehmi, W Sakr, Z Nahleh, Y Hussein, M Ibrahim, B Albashiti, K Hayek, I Khalifeh, S Bandyopadhyay. Wayne State University, Detroit, MI; Karmanos Cancer Institute, Detroit, MI; American University of Beirut, Beirut, Lebanon

Background: Determining ER, PR and Her-2/neu expression status in microinvasive carcinoma is often hampered by the lack of adequate microinvasive component on the additional tissue sections used for immunohistochemical (IHC) evaluation. Our objective was to correlate the IHC status of ER-PR and Her-2/neu in a cohort of patients with coexistent ductal carcinoma in situ (DCIS) and invasive carcinoma (IC) including a subset of patients with microinvasive carcinoma (MIC).
Design: From our pathology archives, we identified 117 consecutive patients with the diagnosis of DCIS and coexistent IC/MIC between 2004-2006. The immunostains for ER/PR and Her-2/neu were performed using established protocols and specific antibodies. For the purpose of this study, the H&E slides and the IHC stains for ER, PR and Her-2/neu receptors were reviewed with the IHC stains evaluated according to the CAP/ASCO guidelines.
Results: Our cohort included 100 patients with DCIS+IC and 17 with DCIS and MIC Ninety-nine (99%) of the DCIS+IC cases exhibited concordance between the DCIS and IC components. This was true for the 51 cases with ER/PR+, Her2 -, the 16 cases with ER/PR+ and Her2 +, the 12 cases with ER/PR- and Her2+ and the 21 cases with ER/PR- and Her2 -. While the ER-PR were concordant in the last case, Her-2/neu was negative in the DCIS and positive in the invasive tumor. Only 7 of the 17 patients with DCIS and MIC tumors had adequate MIC component for IHC evaluation with 100% concordance.
Conclusions: Accurate determination of ER-PR and Her2 neu status is an essential component of the pathological evaluation of mammary neoplasia with major management implications. Our data show a 99% concordance between the DCIS and IC and 100% concordance between DCIS and MIC. Despite the smaller number available in the MIC category, our results suggest that the minimally invasive disease is likely to mirror the ER-PR and Her2 neu status of its coexistent DCIS.
Category: Breast

Tuesday, March 23, 2010 1:00 PM

Poster Session IV # 4, Tuesday Afternoon

 

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