Can someone help me answer this estrogen thing ...

[emmasmom]

I posted about the return of my menstural cycle earlier in the week. Maryanne responded that the HER2 gene feeds off of estrogen. I am confused, I didn't think that was the case. I am not ER/PR - so I thought as far as the estrogen factor I thought I was o.k. Thanks!

Lisa

[Becky]

Her2 does not feed off of estrogen. If your cancer is also hormone positive (ER+/PR+) these receptors love to cross talk to the Her2 receptor. So, in that sense, they “feed” off each other by exciting each other (and causing signals that lead to phosphorylation and then cell division). There are theories that Her2+ bc comes about from being in a hyper estrogen state but what this means is that perhaps the birth control pill, hormone replacement therapy, exposure to toxins that are like estrogen (pesticides for example) or combinations thereof can be a component (one of the straws that breaks the camel’s back). But this is a remote theory and based more on lifetime exposures (for example, lets say you took the birth control pill and then later hormone replacement therapy. You ate a lot of beef and dairy (non organic so had estrogen exposure there) and you lived where they sprayed pesticides etc – I think you get the picture. However, pregnancy and miscarriage can also be a hyper hormone time of life too). If you are ER+and/ or PR+, you do need to take an anti hormonal (like tamoxifen or an aromatase inhibitor) to also shut down the hormone receptors. Shutdown them down in conjunction with Herceptin (to shutdown the Her2 receptor) is a one-two punch.




I hope this helps and alleviates any undue worries.



Kind regards



Becky

[sarah]

Becky,
Thanks for this explanation. I had also read on this site about the cross connection and as a triple positive, I wondered what happens when you stop either Herceptin or an AI? Does that zap up the other and put you in added danger?
Sarah