[wizzwizz4]

> Breast cancer is generally thought to be caused by excessively high estrogen levels.

If by "excessively high", you mean the normal range for pre-menopausal adult women, then yes. Otherwise, citation needed. Afaik, breast cancer is thought to be caused primarily by having breast tissue, and secondarily by the response of breast tissue to normal levels of estrogen. (People with higher estrogen levels than average tend to have more breast tissue, but that's more because they tend to have breasts than because of any impact estrogen has on the rest of the body – unlike people with lower estrogen levels than average, who tend to be men.)

And yes, estrogen blockers / SERMs are a good treatment for some breast cancers, but they don't eliminate breast cancer risk. Even cis men who have relatively low estrogen levels and hardly any breast tissue can get breast cancer.

[tempsy]

"Estrogen a more powerful breast cancer culprit than we realized"

https://news.harvard.edu/gazette/story/2023/05/estrogen-a-mo...

[wizzwizz4]

This article buries the lede, but boy is that lede fascinating.

> Estrogen receptors are known to bind to certain regions of the genome when a cell is stimulated by estrogen. The researchers found that these estrogen-binding sites were frequently next to the zones where the early DNA breaks took place.

Estrogens are important for other things, so (what's effectively) menopause would be a rather impractical preventative measure for most people – but knowledge is still power. I'll have to read the paper sometime.

https://doi.org/10.1038/s41586-023-06057-w