[231] The Evaluation of the Breast Biomarkers in Multifocal/Multicentric Breast Carcinomas.

Melike Pekmezci, Alia Salhadar, Prabha Rajan, Cagatay Ersahin. Loyola University Medical Center, Maywood, IL

Background: There are controversies regarding the diagnostic and therapeutic management of multifocal/multicentric (MF/MC) breast carcinomas. Estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki67 are well accepted biomarkers in the management of breast carcinomas. However, it is not clear whether repeating these biomarkers in each tumor focus is necessary or has diagnostic value. The purpose of this study is to evaluate whether breast carcinoma biomarkers vary among separate tumor foci of MF/MC breast carcinomas, and whether this variation correlates with the morphological features.
Design: We have reviewed MF/MC invasive breast carcinomas diagnosed between January 2001 and June 2010 at our institution. Cases with biomarker analyses performed on more than one focus were included in the study. Tumor morphology, Nottingham grade, Ki67, ER, PR and HER2 status were evaluated. ER, PR and HER2 results were classified as positive or negative. ER/PR positivity is immunohistochemical (IHC) staining of minimum 1% of the tumor cells, and HER2 positivity is IHC staining of 3+ (uniform, intense membrane staining of >30% of invasive tumor cells) or a positive flourescent in situ hybridization test. Ki67 results were classified as favorable (<10%), intermediate (10-20%) and unfavorable (>20%).
Results: Of 20 MF/MC breast carcinomas included in the study, only 2 cases had tumors with variable morphology in different foci. The tumor marker characteristics of these 2 cases were presented in table1.

Tumor marker characteristics of cases with variable morphology
  MorphologyERPRHER2Ki67
CASE 1Tumor 1DuctalGrade 1+++10-20%
 Tumor 2LobularGrade 1+++10-20%
CASE 2Tumor 1DuctalGrade 2++-10-20%
 Tumor 2DuctalGrade 3--->20%


The remainder of 18 MF/MC breast carcinomas with uniform morphology showed identical ER, PR, HER2 and Ki67 results in both foci.
Conclusions: Morphologically similar tumors from different foci of MF/MC breast carcinomas show identical ER, PR, HER2 and Ki67 results. Testing of these biomarkers at more than one focus is not necessary during the histopathological evaluation of the MF/MC breast carcinomas. Presence of variations in morphology including tumor architecture and Nottingham grade warrants the analysis of biomarkers on multiple foci.
Category: Breast

Wednesday, March 2, 2011 1:00 PM

Poster Session VI # 20, Wednesday Afternoon

 

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