Ethnic Disparities in Breast Tumor Phenotypic Subtypes in Hispanic and Non-Hispanic White Women

ArticleinJournal of Women's Health 20(10):1543-50 · July 2011with7 Reads
DOI: 10.1089/jwh.2010.2558 · Source: PubMed
Abstract
Hispanic women are at a lower risk of getting breast cancer than non-Hispanic white (NHW) women, yet they experience a higher risk of mortality after diagnosis. There is some evidence to suggest differences in tumor pathology; however, very limited research has been published on Hispanic women. This represents one of the first studies to evaluate the prevalence of tumor markers and phenotypic subtypes that are associated with poorer prognosis (human epidermal growth factor receptor 2 [HER2], triple negative and basal-like tumors) among Hispanic women. We reviewed pathology reports, obtained paraffin blocks of breast cancer tissue, and established tissue microarrays from NHW (n=119) and Hispanic women (n=69) who were Colorado participants in the 4-Corners Breast Cancer Study. We evaluated ethnic differences in the prevalence of tumor markers and phenotypic subtypes and assessed the contribution of risk factors in explaining the observed differences. Consistent with other studies, Hispanic women had a higher prevalence of estrogen receptor-negative tumors compared with NHWs (36.2% vs. 22.7%, p=0.05). Hispanics also had an unexpectedly higher proportion of HER2-positive tumors compared with NHWs (31.9% vs. 14.3%, p<0.01). Independent of other prognostic factors, Hispanics were 2.8 times more likely to have a HER2-positive tumor (95% confidence interval [CI] 0.98-7.86). Hispanics were less likely to have the more favorable luminal A subtype, but no significant differences were observed for the less favorable basal-like or triple negative subtypes. However, there were suggestive differences when considering menopausal status. These findings provide evidence that breast cancers among Hispanic women comprise a distinct spectrum of tumor subtypes when compared with NHW women.
    • "ERBB2 copy number gain) and in line with the rates of ERBB2 protein expression reported in most of the African-American patient studies [Fregene and Newman, 2005; Adebamowo et al., 2008, Ma et al., 2013. The incidence of ER-and PR-negative expressed breast tumors is found to be higher among African-American and Hispanic women compared to other groups [O'Brien et al., 2010; Hines et al., 2011; Cui et al., 2014]. The DLX4 gene and its mRNA and protein BP1 was found to be associated with ER and PR negativity in both clinical cases and breast cancer cell lines [Fu et al., 2003]. "
    [Show abstract] [Hide abstract] ABSTRACT: Breast cancer is one of the main causes of cancer death among South African women. Although several risk factors can be attributed to the observed high mortality rate, the biology of the tumors is not extensively investigated. Copy number gain of the DLX4 homeobox gene has been observed in breast cancer in association with poor prognosis and specific racial groups. Therefore, we aimed to assess the copy number and prognostic role of DLX4 in breast cancer from South African patients. Due to the co-location of ERBB2 and DLX4 in the 17q21 region, its copy number was also evaluated. Our results in the analysis of 66 cases demonstrated copy number gains of DLX4 and ERBB2 in 24.1 and 29.7% of the cases, respectively. Linear regression analysis showed no dependency between the copy number alterations in these genes. Although not significant, patients with DLX4 and ERBB2 gains presented a higher frequency of advanced-grade tumors. In addition, copy number alterations of these genes were not significantly differently observed in the 3 main racial groups of the Western Cape population: Colored, White, and Black. These findings indicate that gains of DLX4 and ERBB2 occur in South African breast cancer patients irrespectively of their race and factors known to influence prognosis.
    Full-text · Article · Nov 2015
    • "African-American and Hispanic/Latina women with breast cancer have poor outcome compared with other groups [1]. Studies have suggested that differences in tumor receptorsubtypes may potentially play a role in the disparate outcomes from breast cancer observed among African-American and Hispanic/Latina women [2,3]. Since the expression of conventional receptor markers ER, PR, HER2 and the proliferative marker, Ki67, guide treatment regimes, they may also play a significant role in predicting outcome [4]. "
    [Show abstract] [Hide abstract] ABSTRACT: Background: African-American women have higher mortality from breast cancer than other ethnic groups. The association between poor survival and differences with tumor phenotypes is not well understood. The purpose of this study is to assess the clinical significance of (1) Stem cell-like markers CD44 and CD24; (2) PI3K/Akt pathway associated targets PTEN, activation of Akt, and FOXO1; and (3) the Insulin-like growth factor-1 (IGF-I) and IGF binding protein-3 (IGFBP3) in different breast cancer subtypes, and compare the differences between African-American and Hispanic/Latina women who have similar social-economic-status. Methods: A total of N=318 African-American and Hispanic/Latina women, with clinically-annotated information within the inclusion criteria were included. Formalin fixed paraffin embedded tissues from these patients were tested for the different markers using immunohistochemistry techniques. Kaplan-Meier survival-curves and Cox-regression analyses were used to assess Relative Risk and Disease-Free-Survival (DFS). Results: The triple-negative-breast-cancer (TNBC) receptor-subtype was more prevalent among premenopausal women, and the Hormonal Receptor (HR) positive subtype was most common overall. TNBC tumors were more likely to have loss of PTEN, express high Ki67, and have increased CD44+/CD24- expression. TNBC was also associated with higher plasma-IGF-I levels. HR-/HER2+ tumors showed high pAkt, decreased FOXO1, and high CD24+ expression. The loss of PTEN impacted DFS significantly in African Americans, but not in Hispanics/Latinas after adjusted for treatment and other tumor pathological factors. The CD44+/CD24- and CD24+/CD44- phenotypes decreased DFS, but were not independent predictors for DFS. HER2-positive and TNBC type of cancers continued to exhibit significant decrease in DFS after adjusting for the selected biomarkers and treatment. Conclusions: TNBC incidence is high among African-American and Hispanic/Latino women residing in South Los Angeles. Our study also shows for the first time that TNBC was significantly associated with PTEN loss, high Ki67 and the CD44+/CD24- phenotype. The loss of PTEN impacts DFS significantly in African Americans.
    Full-text · Article · Oct 2013
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