Hi wuzzie,
I think alcohol exerts its own effects, independently of HRT, and yes, if oral HRT is taken, both alcohol and HRT will be metabolised by the liver, but I'm not aware of liver metabolites directly affecting breast tissue. According to
https://www.breastcancer.org/risk/factors/alcohol'Research consistently shows that drinking alcoholic beverages -- beer, wine, and liquor -- increases a woman's risk of hormone-receptor-positive breast cancer. Alcohol can increase levels of estrogen and other hormones associated with hormone-receptor-positive breast cancer. Alcohol also may increase breast cancer risk by damaging DNA in cells.'
I personally haven't read many articles on the mechanism of alcohol regarding breast cancer, but it's interesting that alcohol can increase levels of oestrogen. I didn't know that.
There are not many robust and long term studies on transdermal HRT, but the ones available show that it is safer than oral pills, because it bypasses first-pass liver metabolism.
As stellajane said, not all women absorb oestrogen well with patches, so many are still on the pill, although they have the gel as another option, apparently gel and patches have different absorption rates for many women.
I'm currently using a transdermal conti regime, but the progestogen in the patch is norethisterone ( which is supposedly one of the older, less breast friendly ones) so I don't know what to think 🤔
I know some women who feel better on the norethisterone patch than on Utrogestan. There is one recent study that has found that micronised progesterone (Utrogestan) also can increase the risk of endometrial cancer.
https://linkinghub.elsevier.com/retrieve/pii/S0378512216301232 so it's a double-edged sword.
My personal view is that every drug carries risks and there's nothing absolutely safe, but you have to weigh up risks and benefits to decide what suits you best. That's why science is so important. I understand that sometimes it's difficult to weigh up risk/benefit because of so many apparently contradictory information, but that's how science works. Even if we knew the precise molecular mechanisms by which hormones act in all types of cells, every person has slightly different genes and extremely variable environmental factors, so in the end it's up to you to decide after seeking information online and with your doctors.
BeaR.