TY - JOUR
T1 - Molecular Breast Cancer Subtypes in Premenopausal and Postmenopausal African-American Women
T2 - Age-Specific Prevalence and Survival
AU - Ihemelandu, Chukwuemeka U.
AU - Leffall, La Salle D.
AU - Dewitty, Robert L.
AU - Naab, Tammey J.
AU - Mezghebe, Haile M.
AU - Makambi, Kepher H.
AU - Adams-Campbell, Lucile
AU - Frederick, Wayne A.
PY - 2007/11/1
Y1 - 2007/11/1
N2 - Background: Breast cancer is currently regarded as a heterogeneous disease classified into various molecular subtypes using gene expression analysis. These molecular subtypes include: basal cell-like, Her-2/neu, luminal A, and luminal B. Objectives: To analyze the prevalence and clinicopathologic associations for molecular breast cancer subtypes in premenopausal and postmenopausal African-American women. Design: A retrospective analysis of all African-American women diagnosed with breast cancer from 1998 to 2005, who had assessable data for ER, PR, and Her-2/neu status. Molecular subtype classification was done based on immunohistochemical surrogates for ER, PR, and Her-2/neu status obtained from Howard University tumor registry for each patient. The molecular subtypes were defined as: luminal A (ER+ and/or PR+, HER2-), luminal B (ER+ and/or PR+, HER2+), basal-like (ER-, PR-, HER2-), and Her-2/neu (ER-, PR-, and HER2+). Outcome Measures: We analyzed the prevalence of molecular breast cancer subtypes in a population of African-American women and determined their associations with patient demographics and clinicopathologic variables: node status, tumor size, histological grade, p53 mutation status, and breast cancer-specific survival. Results: The luminal A subtype was the most prevalent in our study sample (55.4%) compared with (11.8%) luminal B, (21.2%) basal cell-like, and (11.6%) Her-2/neu subtypes. The molecular subtypes did not differ by menopausal status. However, when stratified into age-specific groups, the basal cell-like subtype (57.1%) was the most prevalent in the age group <35 y compared with luminal A, luminal B, and Her-2/neu subtypes at 25.0%, 14.3%, and 3.6%, respectively. The basal cell-like subtype also showed an age-specific bimodal distribution with a peak in the <35 y and 51 to 65 y age groups. The basal cell-like and the Her-2/neu subtypes showed an increased association with clinicopathologic variables portending a more aggressive clinical course when compared with luminal A subtype. A paradoxical inverse relationship between the expression of p53 and Bcl-2 protooncoprotein was noted in the molecular subtypes. Breast cancer-specific survival differed significantly among the molecular subtypes (P < 0.04), with the basal cell-like and Her-2/neu subtypes having the poorest outcome. Conclusions: The high prevalence of the basal cell-like subtype in the young premenopausal African-American women aged <35 y could be a contributory factor to the poorer prognosis of breast cancer observed in this cohort of patients.
AB - Background: Breast cancer is currently regarded as a heterogeneous disease classified into various molecular subtypes using gene expression analysis. These molecular subtypes include: basal cell-like, Her-2/neu, luminal A, and luminal B. Objectives: To analyze the prevalence and clinicopathologic associations for molecular breast cancer subtypes in premenopausal and postmenopausal African-American women. Design: A retrospective analysis of all African-American women diagnosed with breast cancer from 1998 to 2005, who had assessable data for ER, PR, and Her-2/neu status. Molecular subtype classification was done based on immunohistochemical surrogates for ER, PR, and Her-2/neu status obtained from Howard University tumor registry for each patient. The molecular subtypes were defined as: luminal A (ER+ and/or PR+, HER2-), luminal B (ER+ and/or PR+, HER2+), basal-like (ER-, PR-, HER2-), and Her-2/neu (ER-, PR-, and HER2+). Outcome Measures: We analyzed the prevalence of molecular breast cancer subtypes in a population of African-American women and determined their associations with patient demographics and clinicopathologic variables: node status, tumor size, histological grade, p53 mutation status, and breast cancer-specific survival. Results: The luminal A subtype was the most prevalent in our study sample (55.4%) compared with (11.8%) luminal B, (21.2%) basal cell-like, and (11.6%) Her-2/neu subtypes. The molecular subtypes did not differ by menopausal status. However, when stratified into age-specific groups, the basal cell-like subtype (57.1%) was the most prevalent in the age group <35 y compared with luminal A, luminal B, and Her-2/neu subtypes at 25.0%, 14.3%, and 3.6%, respectively. The basal cell-like subtype also showed an age-specific bimodal distribution with a peak in the <35 y and 51 to 65 y age groups. The basal cell-like and the Her-2/neu subtypes showed an increased association with clinicopathologic variables portending a more aggressive clinical course when compared with luminal A subtype. A paradoxical inverse relationship between the expression of p53 and Bcl-2 protooncoprotein was noted in the molecular subtypes. Breast cancer-specific survival differed significantly among the molecular subtypes (P < 0.04), with the basal cell-like and Her-2/neu subtypes having the poorest outcome. Conclusions: The high prevalence of the basal cell-like subtype in the young premenopausal African-American women aged <35 y could be a contributory factor to the poorer prognosis of breast cancer observed in this cohort of patients.
KW - African-American women
KW - molecular breast cancer subtypes
KW - postmenopausal
KW - premenopausal
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U2 - 10.1016/j.jss.2007.03.085
DO - 10.1016/j.jss.2007.03.085
M3 - Article
C2 - 17950079
AN - SCOPUS:35248837469
SN - 0022-4804
VL - 143
SP - 109
EP - 118
JO - Journal of Surgical Research
JF - Journal of Surgical Research
IS - 1
ER -