Research has shown that breast cancer is diagnosed more or less frequently in different ethnic groups in the United States. But scientists aren't sure why these differences happen. Differences in genetics might be part of the explanation. External factors, such as diet and lifestyle choices, also probably contribute to these differences.
A study looked at whether differences in hormone levels could help explain differences in breast cancer rates. While the results don't provide all the answers, they do offer more information. For example, Japanese American women and native Hawaiian women have a higher than average risk of breast cancer and their estrogen levels were found to be higher than average. On the other hand, Black women have a lower risk of breast cancer than white women, but in this study, Black women had higher estrogen levels than white women.
The study also showed that average estrogen levels of Japanese American women have been rising over time. The reason for this is unclear, and it is not clear that an increase in breast cancer risk will follow.
Stay tuned to Breastcancer.org for the latest updates on this important area.