Differential expression of HER-2/NEU receptor of invasive mammary carcinoma between Caucasian and African American patients in the Detroit metropolitan area. Correlation with overall survival and other prognostic factors

Goals. HER-2/neu overexpression in invasive mammary carcinoma is associated with more aggressive biologic behavior. Breast cancer in African American (AA) women has been associated with a shorter survival rate than that seen in Caucasians (C). This study evaluated the frequency of HER-2/neu overexpression in C compared to AA patients and the association of HER-2/neu expression with overall survival and other prognostic factors. Methods. A retrospective review of the SEER data of Karmanos Cancer Institute for patients with invasive mammary carcinoma was conducted between 1998 and 2001. Pathology reports and pathology slides were obtained for those patients with missing data. Available data and material on 608 patients were found. The median follow-up interval was 35 months with a range of 1-91 months. 46.7% of the study population was C while 53.3% was AA. The differential of HER-2/neu expression in C and AA was evaluated. The association of HER-2/neu expression and other prognostic factors with overall survival was carried out by univariate and multivariable analyses using Cox's proportional hazards regression model. Principle results. No statistically significant difference was found in HER-2/neu expression between C and AA patients. Overexpression of HER-2/neu did not correlate with decreased overall survival in this analysis. Major conclusions. Breast cancer HER-2/neu expression in AA patients is not statistically different from that of Caucasians. HER-2/neu expression is not associated with overall survival. Among the other prognostic factors analyzed, ER status and histologic grade were not statistically significant.