is tamoxifen safe for Her 2 ladies?

I have been taking Tamoxifen with Herceptin now for over three years.  I did get a blood test to make sure I metabolize it well and I guess I am a great metabolizer of Tamoxifen so I will likely stay on it for two more years.   I haven't any issues with it. 

Jennifer

evebarry,

I'm not terrific at this so take it with a grain of sand and do further research and ask your doctor. Please don't just assume this is accurate; but it is one explanation I found on the net regarding tamoxifen and HER2 and AIB1 from 2006:

Up-regulation of estrogen receptor by tamoxifen in human breast cancer - Noguchi - 2006 - Cancer - Wiley Online Library

Conclusions. These results demonstrated that tamoxifen up-regulates ER and PR in human breast cancer.

Nolvadex - drugs informations

Tamoxifen binds to estrogen receptor (ER) which in turn interacts with DNA. The ER/tamoxifen complex recruits other proteins known as co-repressors to stop genes being switched on by estrogen. Some of these proteins include NCoR and SMRT. tamoxifen function can be regulated by a number of different variables including growth factors. tamoxifen needs to block growth factor proteins such as ErbB2/HER2 because high levels of ErbB2 have been shown to occur in tamoxifen resistant cancers. tamoxifen seems to require a protein PAX2 for its full anticancer effect. In the presence of high PAX2 expression, the tamoxifen/estrogen receptor complex is able to suppress the expression of the pro-proliferative ERBB2 protein. In contrast, when AIB-1 expression is higher than PAX2, tamoxifen/estrogen receptor complex upregulates the expression of ERBB2 resulting in stimulation of breast cancer growth.

Don't know if this link will work or not.... something for you to discuss with your doctor:

Cell Signaling & Molecular Targets in Cancer - Google Books Result

books.google.com/books?isbn=146140729X...Malay Chatterjee, Khosrow Kashfi - 2011 - Medical - 375 pages
Overexpression of AIB1 and HER2/NEU Correlates with Tamoxifen Resistance Primary tumors are mostly classified as ER-positive or HER2/Neu-positive based ...

Let me clarify when I say I haven't had issues with it doesn't mean I don't have side effects ... oh yes hot flashes and joint pain for sure!! 

Jennifer 

My onc told me same thing.  I'm worried about Tamoxifen because of my history of blood clots.  She basically said I may as well be pissin' in the wind if I take an AI since I'm pre-menopausal.

Thanks for the feedback on your visit with your onco and his honest but inconclusive responses. Yours are not easy decisions. Ovarian ablation can make a difference.

A.A.

evebarry,

In a way the answer is "no" and in a way the answer is "probably". 

AI's and tamoxifen are (in my personal language, but probably not in the general medical language) metabolic drugs because they act on metabolic processes. AI's are aromatase inhibitors that act on the fat tissues that produce aromatase. The more fat you have, the more that an aromatase inhibitor is helpful. So.... here once again is evidence that fatty weight matters for breast cancer patients. As an aside and just general info, chemopause/menopause brings about a change in the proportion of our muscle tissue to our fatty tissue, increasing the amount of fatty tissue and decreasing the amount of muscle. This is due to the hormonal changes brought about by chemopause/menopause, such as a huge drop in our testosterone. Testosterone of course is what helps to build and maintain muscle tissue.

So if you do the types of exercise that maintain a significant amount of muscle tissue, which usually reduces the amount of fatty tissue, that is one way to try to substitute for taking an AI.

Another possible helper for this that is currently still being investigated is the use of the drug used for diabetes, metformin. There are various theories about how it works. One of them is called the "reverse Warburg effect", by Dr. Lisanti.  As a drug used for diabetes, it too can help control weight (and thus, hopefully, the amount of fatty tissue).

A.A.

P.S. There are still questions about the possibility also of taking some minimal supplemental testosterone to help build the muscle. Ask your doctor. I'd be interested in what she has to say since I don't see any onc now, and studies have been done over time about it. In fact, I was a particant in one. (At the time, I was considered an idiot by many other bc patients for being willing as a breast cancer patient to participate by taking a small dose of testosterone in cream and applying it to the skin for a month for the trial, to see if it helped with sexual dysfunction from chemopause.)

Hi mmm5,

I remember some of our posts together from long ago about it. I don't know where that issue stands now but I haven't heard that it has been solved.

evebarry is postmenopausal so I wonder how that would matter or not with the use of the Zoladex.

A.A.

Mmm5, our dx look almost the same. Im trying to decide about tamox as I will finish taxol/herceptin in 3 weeks with herceptin to continue til nov. Did u take tamox and zoladex or just zoladex? Im also going to talk to my onc about an ooph. Did your onc give you an opinion on that? So much to consider- I wish it was one simpler answer. Thanks.

Thanks for your reply mmm5, you're right about looking at standard of care - its easy to get caught up in all the what ifs & various opinions, and I guess that's what has me so obsessed with whether tamox is best. Im 41 & my onc is recommending tamox, at least for now. Im going to talk it over with onc again until I feel as comfortable as possible.

Hi Jackboo, I posted on another thread of yours about having an ooph, but have found it an interesting discussion.

mm5 my Onc says the same as yours, and did not prescribe Tamox to me, he says there is evidence that it's not as effective for Her2 BC, from my reading I agree with him.  I went straight onto Arimidex post Chemo/Rads as I was in menopause post Chemo (dx at 40). My BMD took a dive after a year on Arimidex and I had to stop it, since I was in menopause and low estrogen, no hormone therapy prescribed.

May last year my period returned, bloods indicated I'm premenopuasal again, periods now regular, Onc discussed Zoladex, Tamox or do nothing  when I saw him in Nov last year.

My hormone receptors were ER 40% PR 20%, I already have osteoporosis from Chemopause and am on Zometa for that, I am thin and very fit so he thought NO hormone manipulation or therapy would be the best option, the SE would out weigh the benefit  for me. 

He also said the recurrence rate for Her2 BC drops at the 3 yr mark and since I will be 3 yrs post dx in a few weeks this was also part of his decision no to recommend OS. He said the trials for Zoladex were only for 2 yrs and I had already had 2 yrs of ovarian suppression with Chemo so didn't think I needed further ovarian suppression. He said if I really needed to treat the hormone part of my BC I could take Tamox but he didn't think it would do anything, maybe reduce my recurrence risk by 2% - I have never discussed recurrence risk with my Onc so not sure about numbers, I'm not a numbers girls. I'm not sure why I got BC in the first place, no risk factors, very fit, healthy, had my kids in my 20's breast fed, no family history etc...........so numbers don't mean much to me. He said it's the Chemo and Herceptin that reduced my risk the most and has always indicated my risk of recureence after ACTH is low and I need to worry about my BMD since I will live another 50 yrs.

I did think about getting a second opinion, but I have a great relationship with my Onc and he is very well respected, widely published and specialises in BC, so have trust in in recommendation which dosen't seem the "standard of care" but best for me.

 Lou

Hi Jackboo, I hope it goes well with the Luporon and the SE are Ok. You know your body the best and you need to feel happy with your treatment. Sometimes it's easy to get caught up with what other treatment women are receiving on these boards, every ones BC is different and the most important thing is that your confident your doing the right treatment for you.

I am fast approaching the 3 yr mark since dx and I do feel really fit and healthy again, my hair is down to my shoulders and no one would ever guess that I had BC, I feel 10 yrs younger than I did a year ago, I found once I finished the Herceptin my energy levels increased and I was able to start running again which is my "time out" activity. I found all my joint aches and pains disappeared once I stooped the AI, I feel like my old self again.

I have always been very relaxed about my BC dx, I'm not a worrier and was lucky to get through treatment with minimal SE, it's funny as I always say that I have no long term SE from the Chemo.........except the osteoporosis!. I'm definitely a glass half full kind of person and don't waste time worrying about things that may never happen, it does get easier the further out from dx for sure.

Hugs and best wishes to you, look forward to your updates.

Lou