Tamoxifen and weakly ER positive women?

[DianneS]

So, I scored a 4 on the Allred test for ER positivity. Not a strong positive....onc says I would benefit about 4-6% from Tamoxifen.

I am struggling with wondering if the side effects are worth taking Tamoxifen.

There are no studies on weakly ER positive women...they lump us in with the strongly positive ER women.

Anyone out there taking Tamoxifen?
Any side effects?

I did the CYP2D6 DNA test to see if I would metabolize Tamoxifen and I am a normal metabolizer. Woopie. That does not mean I get increased benefit - still 4-6%.

I am afraid to begin as I had a tough time with Herceptin, feeling achy and tired. Thanks for any input,

Dianne

[Becky]

Dianne

I guess you need to determine what does that 4% - 6% really mean. For the purposes of my little exercise, I'll use 5%.

Let's say your chance of recurring is 10%. Did your onc mean it gives you a solid 5% meaning now your chance of recurring is 95% or does it dimish your chance of the recurrance rate by 5% meaning now your chance of recurring is 90.5%. I don't think anything is worth that half a percent (IMHO) but a true 5% just might be for many women.

Also, if your chance of recurring is 50% and you get a solid 5% from Tamoxifen, then you only go up to 55% but on the recurrence diminish rate, you are almost at parity at 52.5%.

So... what does your onc mean and what does it mean to you.

Everyone has different rationale in their treatment and what makes sense for you as an individual. Some people will do anything for even a half of a percent and others might want a 25% - 35% benefit or better to try something. Its up to you.

[DianneS]

Hi Becky,

I assume that women who are strongly ER+ receive much more benefit than women who are not strongly ER+. My onc & I did not discuss those strongly ER women as it didn't apply to me. The lower the ER+ the lower the response to Tamoxifen or the AI's. The more questions I ask my doc, the more I seem to find out they don't know. Medicine is not a science - it's an art and an inexact one, at that. They don't know what dose is optimal, they don't know how long one should take Tam or the AI's, they don't know when someone should begin taking them (during Herceptin, or after, and how long after) and then there is the question of becoming resistent to these drugs.

I am starting to feel more like myself since finishing herceptin. It is difficult to pick a day to make myself yucky again. Tamoxifen has so many side effects and the blood clot issues surely scares the heck out of me. I know it is my decision but I'd like to make an informed decision and I don't feel my onc is giving me adequate info, mostly because I guess there just isn't any.

May I ask, Becky, how strongly ER positive you are? Did your onc give you any stats?

Thank you for replying, much appreciated!
Dianne

[Becky]

Dianne

I was 50%ER+ and PR negative. There are studies on metastatic women where only Herceptin and an AI were used first line where there was great response and disease free progression for over 2 years. Therefore, it did prove the combo works. Although not done in early stage, the premise should still hold.

You should discuss with your onc the trials of ER+ but PR neg as Tamoxifen does not do a good job. This is why when I regained my premenopausal status I had my ovaries removed to use Arimidex (even though the jury is still out on that now too). However, I am happy that I was on the AI/Herceptin combo for a full year and I am sure if any cancer cells remained after chemo, that combo got them.

You need to do research or come to peace with yourself with your doctor's guidance on whether you should do hormonal treatment or not.