African ancestry and higher prevalence of triple‐negative breast cancer

Abstract

BACKGROUND The study of breast cancer in women with African ancestry offers the promise of identifying markers for risk assessment and treatment of triple-negative disease. METHODS African American and white American women with invasive cancer diagnosed at the Henry Ford Health System comprised the primary study population, and Ghanaian patients diagnosed and/or treated at the Komfo Anokye Teaching Hospital in Kumasi, Ghana constituted the comparison group. Formalin-fixed, paraffin-embedded specimens were transported to the University of Michigan for histopathology confirmation, and assessment of estrogen and progesterone receptors and HER-2/neu expression. RESULTS The study population included 1008 white Americans, 581 African Americans, and 75 Ghanaians. Mean age at diagnosis was 48.0 years for Ghanaian, 60.8 years for African American, and 62.4 for white American cases (P =.002). Proportions of Ghanaian, African American, and white American cases with estrogen receptor-negative tumors were 76%, 36%, and 22%, respectively (P < .001), and proportions with triple-negative disease were 82%, 26%, and 16%, respectively (P < .001). All Ghanaian cases were palpable, locally advanced cancers; 57 (76%) were grade 3. A total of 147 American women were diagnosed as stage III or IV; of these, 67.5% (n =46) of African Americans and 44.6% (n = 29) of white Americans were grade 3. Among palpable, grade 3 cancers, Ghanaians had the highest prevalence of triple-negative tumors (82.2%), followed by African Americans (32.8%) and white Americans (10.2%). CONCLUSIONS Our study demonstrates progressively increasing frequency of estrogen receptor-negative and triple-negative tumors among breast cancer patients with white American, African American, and Ghanaian/African backgrounds. This pattern indicates a need for additional investigations correlating the extent of African ancestry and high-risk breast cancer subtypes.

Survival Outcomes of Breast Cancer in Ghana: An Analysis of Clinicopathological Features

“…Breast cancer in African women tend to be the ag- gressive triple negative subtype, [24] [36] similar to those observed in African-American women in the US, and is non-responsive to commonly used therapeutic drugs.…”

“…In addition, a study has shown that Ghanaian women are more likely to be diagnosed with high-grade tumors that are triple negative breast tumor [24]. Explanations for the delayed presentation among Ghanaian women have been traced to the cost of, and access to, routine screening mammography, lack of awareness, and cultural attitudes [24].…”

“…In addition, a study has shown that Ghanaian women are more likely to be diagnosed with high-grade tumors that are triple negative breast tumor [24]. Explanations for the delayed presentation among Ghanaian women have been traced to the cost of, and access to, routine screening mammography, lack of awareness, and cultural attitudes [24]. Harsh social stigma, fear of mastectomy or death, and the appeal of traditional healers over doctors have also been cited as some of the cultural reasons for late presentation of cases in Ghana [25].…”

AACR Cancer Progress Report 2012

“…Triple negative breast cancer is significantly higher in African American women than all other ethnicities (138,139).…”

Determinants and Disparities of Survival in Triple-Negative Breast Cancer Patients: A Population-Based Retrospective Longitudinal Cohort Design Utilizing the Cox Proportional Hazard Analytical Model

“…Even in an international study involving women of African ancestry, the racial disparity persisted (Stark et al, 2010). Premenopausal women tend to be at greatest risk of developing TNBC and up to 39% of all African American premenopausal women have TNBC (Carey et al, 2006).…”