PSA drop with decreasing Testosterone after Estrogen Patch Therapy

[janebob99]

Here's a plot that I made from data taken from the PATCH estrogen patch therapy study. It plots the % reduction in PSA from baseline (100%) at time = 0 as a function of testosterone levels over a period of 4 weeks.

As you know, estrogen effectively castrates men, causing a drop in testosterone over time to castrate levels (< 50 ng/dL). My question was: is this a linear relationship? The answer is "Yes", and one can extrapolate the trend a short distance down to zero PSA at zero testosterone level.

It's exciting to discover linear relationships from complex data sets!

Bob

[KocoPr]

I guess the questions are can it be sustained?

Can someone that is hormone sensitive and on ADT switch to estrogen? Even better can one go back and forth from ADT to Estrogen when one starts to fail? I am kinda doing that with BAT. High T then ADT rinse and repeat depending on PSA levels.

What are the side effects from long term E2 patches?

[janebob99 in reply to KocoPr]

In principle, you can substitute Lupron ADT with Estrogen. Both castrate men via the same mechanism of LSH and FH suppression. So, BAT should work the same with estrogen patches/gels, but with fewer side effects. That would be a great question for Dr. Demanes.

The main side effect of long term E2 patches is gynecomastia, which causes breast enlargement in varying degrees in some men. Other side effects are increased relative risk of breast cancer (even still, the absolute risk of BC is still very, very low for MEN, especially if you don't have BRCA 1/2 mutations). You'd want to get a free genetic test from PROMISE/Color before starting E2 therapy. It was quick and easy (saliva test).