About 70 percent of women who are diagnosed with breast cancer have no identifiable risk factors. But since we really don't know the cause of breast cancer, there's very little you can do to prevent it. The truth is that although more white women are diagnosed with breast cancer, a greater percentage of African-American women who have the disease will die of it. The rate of diagnosis is 13 percent higher among white women. But after five years, only 71 percent of African American women diagnosed with breast cancer are alive, compared to 86 percent of white women, according to the American Cancer Society.
Most experts attribute the difference to black women's poorer access to health care.
As a group, white, Hawaiian, and black women have the highest rates of the disease, according to the National Cancer Institute. The lowest rates occur among American Indian, Vietnamese, and Korean women. No one knows what accounts for this, although there are unproven theories that the groups with less breast cancer consume less fat. Some researchers and advocates for women with the disease say there's a correlation between breast cancer incidence and industrial pollutants. The notion is that the chemicals migrate from under the arms into the lymph nodes and interfere with lymph circulation, but researchers have dismissed this theory.