African-American women with breast cancer are more likely than Caucasian women to present with late stage, higher grade tumors, according to a report in the July 9th advance edition of Cancer.
Previous epidemiological studies have shown that breast carcinomas in African-American women present with have more aggressive characteristics than do breast carcinomas in Caucasian women, the authors explain.
Dr. Gloria J. Morris and associates from Thomas Jefferson University Hospital in Philadelphia compared pathology data, nuclear grade, Ki-67, c-erb-B2, and p53 expression in tumors from 2230 African-American and Caucasian women diagnosed with breast cancer between 1995 and 2002.
A greater percentage of African-American than Caucasian women presented with advanced stage tumors (stages III/IV), the authors report, and African-American women were more likely than Caucasian women to present with a higher histologic grade.
Estrogen receptor positivity was less common among African-American patients than among Caucasian patients, but progesterone receptor positivity did not differ between the groups.
Ki-67 and p53 expression was significantly higher in tumors from African-American women, the researchers note. Expression of c-erb-B2, p21, and bcl-2 did not differ between African-American and Caucasian women.
The aggressive triple-negative (basal-like, negative for estrogen receptors, progesterone receptors, and HER-2) phenotype was twice as common among African-American women (20.8%) than among Caucasian women (10.4%).
Survival was lower among African-American women, especially among those with Ki-67-positive tumors, the report indicates.
“These data are consistent with other large population-based studies of racial differences in breast carcinoma presentation at the time of diagnosis,” the investigators write.
“Comprehensive genomic expression profiling studies that compare mRNA arrays from tumors matched with regard to clinical characteristics but from patients of different ethnic backgrounds will become extremely valuable in defining (a) unique set(s) of genes that may drive tumor growth in 1 patient population more than another,” the authors conclude. “More future studies identifying differences in gene expression will help to target and enhance treatments more specifically.”