Advanced stages and poorly differentiated grade are associated with an increased risk of HER2/neu positive breast carcinoma only in White women: findings from a prospective cohort study of African-American and White-American women

Abstract

The risk of HER2/neu positive breast carcinoma differs between African-American and White women. For White women only, this risk was statistically significant and increased almost linearly within each TNM stage with grade dedifferentiation. The statistically significantly higher prevalence of "ER(-)/PR(-), HER2(- )" phenotype in African American women potentially is the attributing factor to observed lack of an association between the risk of HER2/neu positive breast carcinoma with advanced stages and poorly differentiated grade. Among women diagnosed with "ER(-)/PR(-), HER2(-)" phenotype the odds ratios of being African-American and pre-menopausal was 1.72 (95% CI 1.17-2.54, P = 0.006) and 1.94 (95% CI 1.27-2.96, P = 0.002), respectively. The histologic features of basal-like and ER(-)/HER2(+ )carcinomas overlaps. Differences in the biology of breast carcinoma between African American and White women are partially attributed to the disparity in more adverse pathologic prognostic indicators at the initial clinical presentation of this disease.

Race and triple negative threats to breast cancer survival: a population-based study in Atlanta, GA

“…A California registry study, although missing nearly 45% of the data to construct triple subtypes, also found the highest prevalence for TNT among AA women (25%), followed by Hispanics (17%), and white women (11%) [28]. Among non-population based studies in Michigan and Philadelphia, higher TNT prevalences among AA women compared to white women have also been noted [29,30]. Similar to previous studies [18,30], we observed no racial differences in the other subtypes, including the other ER-PR-subtype (ER-PR-HER2+).…”

“…Racial identity was selfreported. The youngest age category (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34) included by necessity a larger range because there were so few cases in this age range as previously described [33]. A poverty index (as an indicator of socio-economic status) was calculated based on the combination of annual household income and the number of people supported by that income, with the annual household income divided by the 1991 national poverty level income for a family of the corresponding size [33,34].…”

“…TNTs account for between 10-30% of all invasive breast cancers in the U.S. and AA women appear to be twice as likely as white women to present with these tumors [18,[28][29][30]. Singly and in combination, the earlier age at onset, lack of viable therapeutic targets and highly aggressive features of the TNTs may contribute to poor outcome and may explain in part the historically poorest survival observed among AA women.…”

“…Singly and in combination, the earlier age at onset, lack of viable therapeutic targets and highly aggressive features of the TNTs may contribute to poor outcome and may explain in part the historically poorest survival observed among AA women. Several U.S. studies have recently reported a higher prevalence of TNTs among younger and African-American women [18,[28][29][30]. However, only two published studies addressing race, breast cancer subtypes, and survival are population-based and both have several limitations [18,28].…”

Common Molecular Mechanisms of Mammary Gland Development and Breast Cancer

“…Basal-like tumours exhibited higher grade, and tended to be found among younger patients: the prevalence was 16 % in premenopausal and 11 % in postmenopausal patients. Several other investigators reported a higher prevalence of ER-negative, PR-negative[41] or triple negative (ER-negative, PR-negative, HER2-negative)[42] breast cancer in younger African American patients. Most recently, Bauer et al[43] found that in a population-based series of 51 074 incident breast cancer cases identified from the California Cancer Registry (United States), the prevalence of triplenegative breast cancer was 12 %.…”