Breast cancer does not affect all women equally. While African American women are less likely than white women to develop breast cancer, when they do get it, it tends to be more life-threatening. Many researchers believe this is partly due to biological differences between breast cancers. In recent years, genetic studies have identified several different subtypes of breast cancer. It has been proposed that African American women may be more likely to develop an aggressive subtype, which may increase their risk of dying from the disease.

A new study in the June 7, 2006 issue of the Journal of the American Medical Association found that young African American women with breast cancer were in fact at an increased risk of having an aggressive subtype.

About the Study

The participants included 496 women in North Carolina who had been diagnosed with breast cancer. Of the participants, 196 were African American and 300 were non-African American (286 white and 14 Native American, Hispanic, Asian American, or multiracial). The researchers performed genetic tests on the women’s tumor tissue and classified their breast cancers as one of five subtypes: basal-like, human epidermal growth factor receptor-2 positive/estrogen receptor negative (HER2+/E-), luminal A, luminal B, or unclassified.

Premenopausal African American women were more likely to have the basal-like breast cancer subtype than postmenopausal women and non-African American women of any age. The luminal A subtype, on the other hand, was less common in premenopausal African American women than the others. The HER2+/E- and luminal B subtypes did not vary among the different race and age groups. Women with the basal-like and HER2+/E-subtypes were less likely to survive than those with luminal A or luminal B subtypes.

How Does This Affect You?

These findings suggest that the higher prevalence of basal-like tumors and the lower prevalence of luminal A tumors in young African American women may contribute to the increased risk of death from breast cancer in African American women. But other factors, such as differences in access to screening and treatment among different races, also likely play a part.

Advances in genetic testing technologies, such as microarray analysis , can determine which genes are turned on and turned off in a tumor. These tests have made it apparent that breast cancer is not one disease, rather a family of biologically distinct diseases—some of which are more aggressive than others. Classifying a breast cancer’s subtype can help guide treatment decisions.

There is a need for new treatments for cancers such as the basal-like subtype. Current treatments are limited, decreasing the likelihood of survival. The most important thing you can do to protect yourself from breast cancer is to get regular healthcare. Early detection can dramatically increase the chances of surviving breast cancer.