The study was conducted by Sinai Urban Health Institute in Chicago and funded by the Avon Foundation for Women. It is the first national study to investigate the racial disparity in breast cancer mortality at the city level in the U.S., the Avon Foundation said.

Researchers analyzed breast cancer deaths reported between 2005 and 2007 against seven societal and ecological risk factors, including race, poverty level, and racial residential segregation. They found that societal issues such as poverty and racial inequities cause most of the disparity in death rates, and genetic factors make up a small portion of it, Avon said.

The group's findings included the following:

• 21 of the 25 largest U.S. cities have a black/white disparity in breast cancer mortality.
• 13 cities have a statistically significant disparity: New York City, Los Angeles, Chicago, Houston, Philadelphia, San Diego, Dallas, Jacksonville, Columbus, Memphis, Seattle, Boston, and Denver (ordered by population size).
• More than one black woman a week dies needlessly in both Chicago and New York City because of the racial disparity.
• Memphis has the highest disparity of the 25 largest cities.
• San Francisco has the smallest disparity of the 25 largest cities.

"When a woman believes genetics causes her disease, it breeds a sense of hopelessness and fear," said lead study author Steve Whitman, PhD. "Our study proves that black women can play an active role in reducing their risk of dying from breast cancer by getting screened and following through with treatment."