Differences in breast carcinoma characteristics in newly diagnosed African-American and Caucasian patients: A single-institution compilation compared with the National Cancer Institute SEER database

Abstract

9670 Background: Invasive breast carcinomas diagnosed in African-American (AA) patients (pts) are described as more aggressive in characteristics as compared with those in Caucasian (C) patients. Methods: We compiled information from the NCI SEER database on stage, histologic grade, estrogen receptor (ER) and progesterone receptor (PR) positivity of breast carcinomas diagnosed in 136,358 AA and C pts between 1990–2000, and compiled the same information, along with nuclear grade, Ki-67, c-erb-B2, p53, p21, and bcl-2 expression in 2,074 AA and C pts diagnosed and treated at Thomas Jefferson University Hospital (TJUH) between 1996–2002. In TJUH specimens, paraffin-embedded formalin-fixed tissue was stained with hematoxylin/eosin, and immunohistochemical markers were assayed using antibodies to the above proteins. Differences in expression were analyzed by Chi-squared tests. Results: At diagnosis, more AA pts presented with advanced stage (AS, III/IV) tumors in both databases, and were more likely to present with higher histologic grade (p<0.001, all stages in NCI SEER; p=0.001 in early stage [ES, I/II] at TJUH), and nuclear grade 3–4 than C pts (51.0% vs. 31.3% in ES, p<0.001). AA pts had lower ER-positivity (52.2% vs. 63.5%, p<0.001) but significantly higher ki-67 (42.0% vs. 25.7%, p<0.001) and p53 expression (18.4% vs. 12.1%, p<0.05) than C pts with ES tumors, and a trend toward lower ER and increased ki-67 expression in AA pts with AS tumors (not significant). PR, C-erb-B2, p21, and bcl-2 expressions were not significantly different between AA and C pts in all stages. Conclusions: AA pts with invasive breast carcinomas are more likely to present with later stage, higher grade, higher ki-67 expression, and less likely to have ER positivity than C pts in both the NCI SEER and TJUH databases. Due to these disparate presentations, molecular studies which may explain these differences, and correlations with survival, are proposed. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Bristol-Myers Squibb, Johnson & Johnson, Novartis, Pfizer, Roche, Sanofi Bristol-Myers Squibb, Celgene, Novartis, Pfizer, Roche