A new study shows Hispanic women have a higher incidence of aggressive forms of breast cancer compared with non-Hispanic white women.

The study, by the Arizona Cancer Center, shows that 42 percent of Hispanic women with breast cancer lack a hormone receptor, or protein, that allows cancer medication to target and destroy cancer cells.

In non-Hispanic white women, it's 33 percent.

Without the receptor, the cancer is harder to cure, said Dr. Maria Elena Martinez, co-director of the Arizona Cancer Centers Cancer Prevention and Control Program and principal investigator of the study.

So Hispanic women with aggressive breast cancer have to resort to more aggressive forms of treatment such as chemotherapy.

Those testing positive for the receptor can use the more common, less aggressive and often more effective, anti-estrogen therapies, Dr. Martinez said.

"Breast cancer is an understudied and poorly understood disease in the U.S. Hispanic population, and we need to understand the magnitude and profile of breast cancer in our Latina population," Dr. Martinez said.

The study looked at 23,657 non-Hispanic white women and 1,837 Hispanic women who had breast cancer cases reported to the cancer registry from 1995 to 2003.