Differential Expression of Syndecan-1/CD138 in Triple Negative Breast Carcinoma and Hormone Receptor Positive Breast Carcinoma
Samip Patel, Cynthia Cohen, Lauren A McLendon, Abbie Husman, Stephen Schmechel, Robert Busch, Keith Stevens, Amy Adams, Gabriela M Oprea. Emory University, Atlanta, GA; University of Minnesota, Minneapolis, MN
Background: Syndecan-1(CD138) is a member of the family transmembrane heparan sulfate proteoglycans, which are involved in cell-to-cell adhesion and the interaction of cells with the extracellular matrix, cell migration and angiogenesis. Altered syndecan-1 expression has been described in carcinogenesis of various tumors in which it correlates with gain of malignant characteristics and adverse outcome. In the breast, syndecan-1 has additionally been correlated with Her2 amplification and hormone receptor negative status. Syndecan-1 expression has not been studied in a large triple-negative breast carcinoma series in comparison with non-triple negative phenotype.
Design: Breast carcinomas over a 7-year period were reviewed. Tissue microarrays were constructed from 263 invasive breast carcinomas. IHC for hormone markers ER, PR, and Her-2 were scored per CAP standards. Her2 was confirmed by reflex FISH for 2+ IHC. The carcinomas were classified as hormone receptor (ER and/or PR)-positive, Her-positive (ER/PR-negative), and triple-negative. IHC for syndecan-1 was performed. Membranous epithelial staining was scored, with 2-3+ in greater than 5% of tumor cells considered positive. Preliminary statistical analysis was performed by Chi-square analysis.
Results: Patient age ranged from 24 to 90 years. 187 triple-negative (TNC), 67 hormone receptor positive, and 8 Her-positive carcinomas were identified. Syndecan-1 IHC results were able to be assessed in 209 cases. 112 of 144 (78%) of triple-negative carcinomas (TNC) were positive for syndecan-1 as compared to 17 of 65 (26%) of the non-TNC (p<0.001). Fewer (13/58, 22%) hormone receptor positive carcinomas were positive for syndecan-1 as compared with the remaining tumors (116/151, 77%). Syndecan-1 expression did not correlate with age, race, and Her2-positivity.
Conclusions: Syndecan-1 expression appears to be high in triple-negative breast cancers, potentially offering a therapeutic target for targeted therapy against these aggressive neoplasms. Syndecan-1 was frequently negative in hormone receptor positive carcinomas, confirming previous reports.
Wednesday, March 21, 2012 1:00 PM
Poster Session VI # 26, Wednesday Afternoon