Researchers in this study wanted to understand how lifetime exposure to estrogen affects the breast and whether it contributes to breast cancer risk. Estrogen is an important hormone for breast development and function, but long-term exposure has also been linked to increased cancer risk. The researchers explored whether estrogen influences biological aging in breast tissue at the molecular level.
To investigate this, they analyzed normal breast tissue samples from healthy women and examined patterns of DNA methylation, which are chemical changes that regulate gene activity and can be used to estimate how “aged” tissue is biologically. They compared these patterns with measures of estrogen exposure, such as reproductive history and hormone use.
The researchers found that higher lifetime estrogen exposure was associated with accelerated biological aging in breast tissue, even in women without cancer. This suggests that estrogen may increase the rate at which breast cells divide and accumulate molecular changes over time.
Overall, the study indicates that estrogen exposure may play a role in shaping the breast environment in ways that could contribute to cancer development.
