Genes tied to racial differences in breast cancer

Based on similarities in breast cancer between African-American women and women in Africa, researchers propose that genetic factors play an important role in the racial differences seen with breast cancer.

Although African-American women are less likely to develop breast cancer than white-American women, their death rates from the disease are higher, Drs. Alero Fregene and Lisa A. Newman note in the medical journal Cancer.

To investigate the potential role of genetics, the researchers, from the University of Michigan in Ann Arbor, reviewed recently published studies looking at breast cancer in Africa.

They found that African women had a 5- to 10-times lower rate of breast cancer compared with women in Western populations. The two researchers suggest that gynecologic and reproductive patterns among African women that minimize exposure to estrogen, such as having periods that begin later in adolescence or having multiple births, may account for these differences.

However, breast cancer death rates are disproportionately high among African women. Although late diagnosis and limited treatment options may play a role, the cancers they develop may simply be more aggressive. This latter possibility is reflected in the lower age of onset and advanced tumors, which are seen among African-American women.

"As research into interactions among tumor biology, genetics, and socioeconomics and/or lifestyle factors continues, medical professionals and researchers will be in a stronger position to address and to eradicate the disproportionate breast cancer burden that currently affects African-American women," the authors conclude.

SOURCE: Cancer, April 15, 2005.