Switching from Tamoxifen to an Aromotase Inhibitor

[ElaineRyan]

Does anyone have any experience with being pre-men. then suppressing your ovarian function and switching to an AI? I know that is what the soft trial is all about but I was just wondering if anyone has done it?

Thx for any feedback.

[Andi]

I am currently on Tamoxifen, but at my December appointment with my oncologist he is going to run the estrogen test to see if I am certifiably menapausal. If I am, he plans to switch me to an AI. I, too, would be interested in knowing if anyone else has done this and if so, how they got along with the change in drugs.

[Becky]

I started out on Tamoxifen but knew that long term, it wasn't the best solution for me because I am only 50% ER+ but I am PR negative. I also was starting my adjuvant Herceptin and although I am not metastatic, Herceptin-Arimidex showed fantastic results (alone) in the metastatic setting. So... I stopped tamoxifen and got my ovaries removed. About 3 weeks after that, I started Arimidex (onc wanted me to wait so my hormones settled down). Then, he kept me on Herceptin an extra 4 months (16 months total) so I was on the Herceptin-Arimidex combo one full year.


On Tamoxifen I occassionally got my period (I am 47 now). I felt bloated and had some minor vision problems. Some hot flashes but not too bad (same with Arimidex and not worse but my mom said going through menopause was a breeze for her with practically no hot flashes so I lucked out there).

I am lucky that I did not get any bone or joint pain on Arimidex but I always exercised and walked alot and take tumeric and omega 3s so maybe that helps. Going through abrupt menopause quickly thins the tissues of the vagina and bladder wall (rather than the natural, gradual process). Although I did not experience terrible dryness (therefore my sex life is fine as well as libido), I did begin to experience bladder infections (4 in 11 months). I do know that it is related to sex (never had a bladder infection in my life prior to this so these 4 were the first ones ever). Went to a urologist and now I have to take one Macrobid 100 after sex. Its working. (Told my mom about this and this happened to her when she went through natural menopause so this may have happened to me anyway and is just one of the problems I would have had like my mom. I mention it just because it did happen to me).

I assume the Arimidex is working because my estrogen is low (onc measured it once and will continue to ensure that estrogen is well below 30 every 6 months or so).

Considering my pathology (negative PR and Her2+) indicates strong possibility of Tamoxifen resistance, I would get an oophorectomy again. Besides that, it is well documented that AIs work better. But everyone needs to make their own decision in this regard.

Let me know if you have any questions, I am happy to help.

[Andi]

Thanks Becky, do you have an opinion as to whether there are differences in the AI's and if so, which one do you think is the best and why.

[Becky]

Dear Andi


Currently there is a major, large study going on that is comparing the three aromatase inhibitors (AIs - Arimidex. Femara and Aromosin). As with studies of this nature, it will take years and years to see if there is a long term difference in disease free survival and overall survival. I believe there won't be a difference in short term results (and probably not long term results either but we do have to wait). That said, Arimidex and Femara work by inhibiting aromatase (an enzyme that helps convert androgens to estrogen) in the same biochemical reaction. Aromosin works in a different way. This is why I have advised women on this board who want to switch from Arimidex to another AI (because of side effects) to switch to Aromosin as Femara works the same way and if they have a bad side effect with Arimidex, they will most likely have the same side effect with Femara (although they may have the same results with Aromosin but it is a better shot that they may not).

There is a study on hormone positive women with bone mets (and only bone mets) where the AIs (all 3) are tested alone. In this test (of only about 20 women) it seemed that Femara worked better but it was a very small study and the result was not statistically significant. See next message as this was deemed too long.

[Becky]

Doctors recommend the following based only upon trial results.

1. If you are postmenopausal and newly diagnosed, they recommend Arimidex due to the trial that compared tamoxifen to arimidex (half the women got tamoxifen and the other half arimidex). Arimidex was much better at reducing recurrence rate than tamoxifen.

2. The "switch" trials. One trial had all the women take tamoxifen and at 2-3 years out, half were switched to Arimidex and the other half stayed on Tamoxifen. Those on Arimidex did better. There was another trial that did exactly the same thing but it used Aromosin instead of Arimidex. In both trials, if you were switched to the AI, you did better than if you stayed on Tamoxifen.

3. There was a trial that all the women took Tamoxifen for 5 years. After that half took nothing and the other half took 5 years of Femara. The women who continued on Femara did better.

So, oncs tend to prescribe the drugs if you fall into the categories above of which there were trials. However, all drugs are on the market and we all know that they are prescibed differently than their FDA approved use.

My initial thoughts are that they are similar/equal as there is absolutely no real data in early bc which is better and IMHO, I think there will not be any statistical difference when the early results of the trial are released (I don't know when that is even though my cousin is in the Arimidex arm).

Hope this helps

[panicked911]

I was one of those wome who optd for ovarian supression. I am strongly er and pr positive as well as her2 positive. Initally my surgeon put me on tamoxifen two weeks after surgery. within two weeks I oticed my breast started to shrink and I felt great. When I went to see oncologost - she said arimidex was a much better way to go . So for now it is monthly lupron shots as i was not even perimenpausal .

I am considering takign my ovaries out and will discuss it with th but there was a study the surgeon and oncoogist when I go back next month. If supressig my ovaries can kep this beast at bay......

Susanne

[mindersue]

Hello,

I'm 38 and currently on Herceptin (10th month) and Aromasin (3rd month). I was eligible for the SOFT trial, but felt that taking the AI was better than Tamoxifen, based on everything I had read. My gyn. almost scared me into going on Tamox. rather than Lupron/AI, saying that menopause at my age would really hurt my quality of life. I really struggled with this, but my gut feeling was take the AI. Then we figured that since I was already in chemopause and managing the side effects okay, menopause wouldn't be any worse.

My onc. prescribed Aromasin. Doing fine on that. I will eventually get my ovaries removed.

I remember having to choose which anti-estrogen therapy, whether or not to participate in the SOFT trial, whether or not to take Lupron / ooph...big decision!!! I just read everything I could find, asked the wonderful people on this board for help (just like you did!), and went with my gut.

Good luck!
Mindy

[Andi]

Thanks Becky for all of the information, it is very helpful.

[astrid]

arimidex.com

femara.com

Aromasin.com

Armidex is Anastrozole

Femeara is Letrozole

Aromasin is Exemestane

As you can see Armidex & Femeara both end in Zole. This means they basically have the same chemical makeup but are manufactured by different companies; However Aromasin is different.

All of these drugs are for use for POST menopausal women. The standard treatment for pre menopausal women is still Tamoxifen. If you are pre menopausal you could talk to your ONC about ovarian suppression or join the SOFT trial. They are still looking for participants. They hope to get 3000 for the trial. I signed up this week.

The SOFT trial is Suppression of Ovarian Function Trial (SOFT). The SOFT trial has three arms. One is Tamoxifen alone (which is the standard treatment used today for pre menopausal women); the second is Tamoxifen plus ovarian suppression and the last is an experimental arm with a post menopausal drug called Exemestane plus ovarian suppression. The ovarian suppression can be done by surgery, radiation or a monthly shot of Triptorelin. For pre menopausal women with estrogen positive breast cancer, it is important to block the estrogen, but AIs are not strong enough to block the estrogen in pre menopausal women. The estrogen in pre menopausal women is produced by the ovaries so shutting them down may be the right course of action. This trial is designed to test if the more aggressive approach will prevent reoccurrences and survival rates.

The arm I was randomized to is Tamoxifen alone. <O

[Cheryl E]

I had 3 oncs tell me to have ovarian suppresion in order to take an AI because the outcome was much better. Although estrogen production can be suppressed in the ovaries by drugs or removal, your adrenal glands still produce estrogen. Thus, the reason for AIs. For me, the choice was easy, as my husband and I knew we were done having kids. I was 40. Actually, it was a relief since my hubbie was too chicken to get a vastectomy. I received 2 rounds of Lupron shots while my body recovered a bit from chemo and breast reconstruction. The oopherectomy was sooooo simple. Up and moving, slowly, the next day. Able to attend a girl's weekend (with dr permission) the next week! That was 3 years ago. About a year ago, I began Vagifem due to vaginal dryness and atrophy. Hot flashes are minimal and no muscle pain/stiffness. I,too, exercise/stretch every day. I am on Femara. My mom is also on femara (although Her2-) without issues.

Cheryl

[VirginiaGirl]

ElaineRyan - I started Tamoxifen in Sept 06 as I was premenopausal, and then had an oophorectomy in October. My onc said then to stay on Tamoxifen for now, but I'm meeting with him tomorrow for a consult to review where we are, and I plan to ask him to put me on an AI instead, probably the Arimidex since there's been so much positive info about it. Will let you know what he says!

God Bless!