At first diagnosis, compared with non-hispanic white women, hispanic women:
- Are younger at the age of first breast cancer diagnosis. This is consistent with the fact that women with breast cancer in Mexico are 10 year younger than in Europe or USA.
- Are 2.7 times more likely to have stage IV breast cancer — that is, cancer that has already spread beyond the breast.
- Have 2.25 times more poorly differentiated tumors — that is, tumors with a cell type that means poorer prognosis.
- Have a twofold risk of larger tumors.
- Have a nearly twofold higher risk of estrogen-negative cancer, meaning that the cancer cannot be treated with some of the most effective cancer drugs.
University of Denver researcher A. Tyler Watlington, MD, MSPH, and colleagues looked at data on 139 Hispanic women and 2,118 non-Hispanic white women enrolled in a Kaiser Permanente health plan for at least three years.
Earlier research has suggested that Hispanic women get more aggressive breast cancer. But most experts thought that in the U.S., Hispanic women’s lesser access to health care explained this disparity. Women who do not get appropriate breast cancer screening tend to have later-stage disease by the time they find out they have cancer.
But Watlington and colleagues found that the differences between Hispanic women and other women persist even when they get exactly the same health care.
“True biologic differences exist in breast cancer by ethnicity,” they suggest.
I must add that there are many factors that should be considered: First, hispanic girls start bleeding earlier that non hispanic, and hispanic women have their menopause later, than non hispanic women. These factors expose hispanic women a longer period to estrogens, that are related to most of the malignant breast tumors.
Other factors that we must consider is diet: hispanic women´s diet is more rich in colesterol because of the large amount of fried food of hispanic diet. Hispanic women also tend to have overweigh and lack of physical activity, which are known risk factors for breast cancer.
Future research, Watlington and colleagues say, should explore these clinical and biological differences “as different strategies for breast cancer prevention may then be warranted for hispanic women.”