Hormones linked with breast cancer risk in blacks
NEW YORK (Reuters Health) - Overall breast cancer rates have fallen among US women in recent years, but haven't significantly changed among young African-American women. The researchers suggest this might be partially explained by cosmetic products containing estrogens and placenta, which are more widely used by African Americans.
Steps must be taken to understand this racial disparity so it can be rectified, co-author Dr. Devra L. Davis, director of the University of Pittsburgh Cancer Institute's Center for Cancer Epidemiology said in a press release accompanying the study.
Davis and her team looked at the incidence of invasive breast cancer among all US women between 1975 and 2002. The current generation of young white women face a 21-percent increased risk of being diagnosed with breast cancer, but that risk is 41-percent higher among young African-American women, they found.
They presented their findings this month in Boston at the American Public Health Association's annual meeting.
While their analysis showed that wider use of breast cancer screening and hormone therapy accounted for much of the increased diagnoses among younger white women, these factors didn't explain black women's increased diagnoses.
As mentioned, Davis and her colleagues suggest that exposure to hormones in cosmetic products could be a factor. In an upcoming report in the journal Medical Hypothesis, they point out that products containing estrogens and placenta are more widely used among African Americans, and that exposure to such products may begin in infancy.
Makers of personal care products are not required to disclose their hormone contents if they are considered "trade secrets," Davis and her team note in the report, even though the Food and Drug Administration currently regards personal care products that contain hormones as drugs and subject to regulation.
At any age, African American women who are diagnosed with breast cancer are more likely to die from the disease than are white women. The researchers also propose that greater exposure to estrogen-containing products could explain why breast cancer is more lethal among African-American women.
"Public disclosure by manufacturers of proprietary hormonally active ingredients is required for this research to move forward," they conclude.
What breastcancer.org says about this article…
Hormones linked with breast cancer risk in blacks
Understanding why different populations have different rates of breast cancer is complex. Genetic factors probably play a role, as do environmental factors. And both genetics and environmental factors can affect each other, causing a multiplied effect. While understanding why different populations have different breast cancer rates is complicated, this knowledge can possibly give us information that will lead to better prevention and treatment.
Diagnoses of invasive breast cancer (breast cancer that has spread beyond the milk ducts or milk lobules) have increased in all women in the United States. But the increase has been much greater in young African American women. More women are being screened for breast cancer and because of this, more women are being diagnosed. Still, the researchers in the article reviewed here said that increased screening did not explain the higher rate of diagnosis in African American women.
The researchers have proposed a theory that might explain the differences. It's important to note that this theory is just that: an unproven theory. No research has been done to prove or disprove it.
Here's what's known:
- Scientists know that hormones affect breast cancer's development and growth.
- Some personal care products more commonly used by African American women contain estrogen and placenta tissue (a source of hormones).
So the researchers suggest that the use personal care products with estrogen and placenta might be part of the reason that white women and African American women have different rates of breast cancer diagnosis.
The answers to many important questions about breast cancer started with a theory. More research is needed to see if personal care products with estrogen and placenta tissue play a role in breast cancer diagnosis.
