An admixture scan in 1,484 African American women with breast cancer.
African American women with breast cancer present more commonly with aggressive tumors that do not express the estrogen receptor (ER) and progesterone receptor (PR) compared with European American women. Whether this disparity is the result of inherited factors has not been established. We did an admixture-based genome-wide scan to search for risk alleles for breast cancer that are highly differentiated in frequency between African American and European American women, and may contribute to specific breast cancer phenotypes, such as ER-negative (ER-) disease. African American women with invasive breast cancer (n = 1,484) were pooled from six population-based studies and typed at approximately 1,500 ancestry-informative markers. We investigated global genetic ancestry and did a whole genome admixture scan searching for breast cancer-predisposing loci in association with disease phenotypes. We found a significant difference in ancestry between ER+PR+ and ER-PR- women, with higher European ancestry among ER+PR+ individuals, after controlling for possible confounders (odds ratios for a 0 to 1 change in European ancestry proportion, 2.84; 95% confidence interval, 1.13-7.14; P = 0.026). Women with localized tumors had higher European ancestry than women with non-localized tumors (odds ratios, 2.65; 95% confidence interval, 1.11-6.35; P = 0.029). No genome-wide statistically significant associations were observed between European or African ancestry at any specific locus and breast cancer, or in analyses stratified by ER/PR status, stage, or grade. In summary, in African American women, genetic ancestry is associated with ER/PR status and disease stage. However, we found little evidence that genetic ancestry at any one region contributes significantly to breast cancer risk or hormone receptor status.
Division of General Internal Medicine, Department of Medicine, Institute for Human Genetics and Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California 94143, USA.
Laura
L
Fejerman
Christopher A
CA
Haiman
David
D
Reich
Arti
A
Tandon
Rahul C
RC
Deo
Esther M
EM
John
Sue A
SA
Ingles
Christine B
CB
Ambrosone
Dana Howard
DH
Bovbjerg
Lina H
LH
Jandorf
Warren
W
Davis
Gregory
G
Ciupak
Alice S
AS
Whittemore
Michael F
MF
Press
Giske
G
Ursin
Leslie
L
Bernstein
Scott
S
Huntsman
Brian E
BE
Henderson
Elad
E
Ziv
Matthew L
ML
Freedman
D000328:Adult; D001741:Black or African American / Q000235:genetics*; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000235:genetics*; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D055106:Genome-Wide Association Study; D006801:Humans; D008875:Middle Aged; D009376:Neoplasms, Hormone-Dependent / Q000235:genetics*; D011379:Prognosis; D011446:Prospective Studies; D011960:Receptors, Estrogen / Q000032:analysis*; D011980:Receptors, Progesterone / Q000032:analysis*; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone