Tamoxifen and NO side effects....worry?

wallycat · July 2007

OK, I've been on Tamoxifen since July 8. The first 2 days I had slight joint pain in my hand and knee; since then, nothing.
I am terrified that I'm not a metabolizer. I will see my onco August 2nd and will show him the studies I've found that indicate women without hot flashes don't do well on tamoxifen in terms of recurrence.

Has anyone without symptoms been tested...the 2D6 thing??
How did it come out?
I'm worried that if I am not getting benefits I am only setting myself up for the side effects....but maybe if I am not a metabolizer I don't get the bad stuff either.

HELP...I'm having an anxiety attack over this!

caaclark · July 2007

I have not been tested but your question is a good one. I hope someone comes along with an answer that will ease your anxiety and mine.

I am also on Tamoxifen and have very little side effects. But....I was thrown into chemopause and had hot flashes a few times a day. Then, when I began taking Tamox. I had them for a few months. Now, I just recently had a hysterectomy and have hot flashes every now and then but really not enough to be bothered by it. Maybe one or two a night.

What research have you seen that says that the absence of symptoms means that you may be a poor metabolizer? Also, even during chemo I had very little side effects (well, except the hair thing). My docs take on it is that I am just lucky. That is what I am hoping too!!

TenderIsOurMight · July 2007

Hi WallyCat,

Only 7% of Caucasian women metabolize Tamoxifen poorly, so the odds are that you metabolize it o.k.

I remember when I started it, I had a couple days only of intense hot flashes, then things settled down. As Tamoxifen is both an estrogen agonist (suggesting it helps keep calcium in bone, and has better effects on lipids, and isn't as drying on vaginal tissue) and antagonist (blocking the estrogen-receptors in tissues so the estrogen-receptor positive cancer cells have competition where they are located, among other pharmacologic mechanisms), it is possible that the feedback to the brain center (the hypothalamus) for hotflashes doesn't drop it's thermostat down as far to cause a hot flash with the frequency of the aromatase inhibitors. The thermostat thing is how I think of the feedback on the brain, but the 'drop' is needed to 'trigger' the hot flash. Not real scientific, but hey.

I also haven't heard that hot flashes absence is a sign of it not working. Why don't you call your oncologist's office and talk with him or her. If needed, we can help you look into the going's about of getting the CYP2D6 test. You are aware that the SSRI's do interfere with Tamoxifen metabolism, right (don't know your circumstances).

Well, hope this helps some.
Tender

Harley44 · July 2007

Hi. I told my onc about the test for tamoxifen, and he told me that I should take it for a month, and if I don't get hot flashes, he would take me off it, because that would indicate that it's not working. Tell your doctor, because that could be a sign that you aren't absorbing it. Are you pre-menopausal? I am post-menopausal, and just getting over the hot flashes, so I don't really want to have to start all over again...

I don't know, because I haven't started yet, because I think I might have to do the chemo first, and I am so scared of the chemo, I just can't seem to get past it! My onc doesn't think I need to do chemo, but I'm having second thoughts.

Good Luck! Let us know what your doc says!

HARLEY

wallycat · July 2007

Hi gals,
I am not taking any other meds...no pain, no brain, no nothin' except vitamins.
I'll post the studies I found. 7% don't metabolize...my luck. I was only at 3% that my thing was cancer.....sigh. I appreciate you guys helping me walk of the proverbial ledge.

Tamoxifen, hot flashes and recurrence in breast cancer.
Mortimer JE, Flatt SW, Parker BA , Gold EB , Wasserman L , Natarajan L , Pierce JP; For the WHEL Study Group.

Cancer Prevention and Control Program, Moores UCSD Cancer Center, University of California, San Diego, La Jolla, CA, 92093-0901, USA, jppierce@ucsd.edu.

We utilized data from the comparison group of the Women's Healthy Eating and Living randomized trial to investigate an "a priori" hypothesis suggested by CYP2D6 studies that hot flashes may be an independent predictor of tamoxifen efficacy. A total of 1551 women with early stage breast cancer were enrolled and randomized to the comparison group of the WHEL multi-institutional trial between 1995 and 2000. Their primary breast cancer diagnoses were between 1991 and 2000. At study entry, 864 (56%) of these women were taking tamoxifen, and hot flashes were reported by 674 (78%). After 7.3 years of follow-up, 127 of those who took tamoxifen at baseline had a confirmed breast cancer recurrence. Women who reported hot flashes at baseline were less likely to develop recurrent breast cancer than those who did not report hot flashes (12.9% vs 21%, P = 0.01). Hot flashes were a stronger predictor of breast cancer specific outcome than age, hormone receptor status, or even the difference in the stage of the cancer at diagnosis (Stage I versus Stage II). These findings suggest an association between side effects, efficacy, and tamoxifen metabolism. The strength of this finding suggests that further study of the relationship between hot flashes and breast cancer progression is warranted. Additional work is warranted to clarify the mechanism of hot flashes in this setting.

PMID: 17541741 [PubMed - as supplied by publisher]

Pharmacogenetics of tamoxifen biotransformation is associated with clinical outcomes of efficacy and hot flashes.
Goetz MP, Rae JM , Suman VJ , Safgren SL, Ames MM, Visscher DW, Reynolds C, Couch FJ, Lingle WL , Flockhart DA , Desta Z , Perez EA, Ingle JN.

Department of Oncology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA. goetz.matthew@mayo.edu

PURPOSE: Polymorphisms in tamoxifen metabolizing genes affect the plasma concentration of tamoxifen metabolites, but their effect on clinical outcome is unknown. METHODS: We determined cytochrome P450 (CYP)2D6 (*4 and *6) and CYP3A5 (*3) genotype from paraffin-embedded tumor samples and buccal cells (living patients) in tamoxifen-treated women enrolled onto a North Central Cancer Treatment Group adjuvant breast cancer trial. The relationship between genotype and disease outcome was determined using the log-rank test and Cox proportional hazards modeling. RESULTS: Paraffin blocks were obtained from 223 of 256 eligible patients, and buccal cells were obtained from 17 living women. CYP2D6 (*4 and *6) and CYP3A5 (*3) genotypes were determined from 190, 194, and 205 patient samples and in 17 living women. The concordance rate between buccal and tumor genotype was 100%. Women with the CYP2D6 *4/*4 genotype had worse relapse-free time (RF-time; P = .023) and disease-free survival (DFS; P = .012), but not overall survival (P = .169) and did not experience moderate to severe hot flashes relative to women heterozygous or homozygous for the wild-type allele. In the multivariate analysis, women with the CYP2D6 *4/*4 genotype still tended to have worse RFS (hazard ratio [HR], 1.85; P = .176) and DFS (HR, 1.86; P = .089). The CYP3A5*3 variant was not associated with any of these clinical outcomes. CONCLUSION: In tamoxifen-treated patients, women with the CYP2D6 *4/*4 genotype tend to have a higher risk of disease relapse and a lower incidence of hot flashes, which is consistent with our previous observation that CYP2D6 is responsible for the metabolic activation of tamoxifen to endoxifen.

PMID: 16361630 [PubMed - indexed for MEDLINE]

kuchagirl · July 2007

I've been on Tam since May 10th. I had a little queasiness the first 2 days, but no side effects since then. I have been missing periods intermittently for 4 years, with only 1 incidence of a hot flash. It makes sense to me that if Tam mimics the symptoms of menopause, and a woman was perimenopausal & not having hot flashes, then she might not have hot flashes on Tam. At least I hope this is true & that I am metabolizing it. At any rate, I like taking a pill every day because I feel like I am doing something to prevent recurrence. There's a psychological value, even if placebo effect.

wallycat · July 2007

Kuchagirl, I also would like a "security blanket" of sorts, but the tamoxifen increases colon cancer, uterine cancer, strokes and blood clots, so if I am not metabolizing it, I'd like to reduce risks for the other cancers and nastier side effects.
I was having occasional night sweats (I just turned 50 and still have too regular a period, darn it!!) but this month, not even that. It doesn't bode well I fear!!

TenderIsOurMight · July 2007

Bummer, and to think I was happy I wasn't flashing on Tamoxifen. I got switched to Arimidex after several years, and I don't flash on that much either (but oh.. the joint pain etc). Wonder if they've looked at that?

Thanks for posting those articles, Wallycat!

mtriso · July 2007

I've been on Tamoxifin for 5 years and I am about to get off of it. I have not had any side effects the entire time. From what you are all saying, it's been a waste of time for me. My oncologist never said this to me and she knew I never had side effects.

Anonymous · July 2007

mtriso----please don't ever feel that taking tamoxifen was a waste of time. My mom took tamox for 7 years and never had any SEs; she is now a survivor of over twenty years without a recurrence!!!! (I've been taking it for over 3.5 years)

Wallycat--while tamox does carry risks for endometrial ca and blood clots, the incidence is very rare (less than 1%). Tamox has not been linked to colon cancer, but bc and colon ca have been called "cancer cousins"; my mom is a survivor of both cancers.

Harley44 · July 2007

Hi... I didn't know that having bc put me at risk for colon cancer, too! Geez! I keep finding out more and more things that frighten me!!

Thanks for the info.

HARLEY

Anonymous · July 2007

smt----having bc does NOT put you at higher risk for colon cancer----the two just sometimes go together in families. Sorry for the confusion!!! you don't need to worry unnecessarily!

Member_of_the_Club · July 2007

My gastroenterologist told me that having had bc does put me at a slightly increased risk for colon cancer. There is some controversy around this but I had a colonoscopy at age 43 for that reason.

Question: What about other side effects on tamoxifen? I have had mild hot flashes on and off since starting it, nothing compared to my chemopause days. But I have had other side effects: nausea the first week or two, bruising for a few months, oh and really bad anxiety attacks. All gone now except the mild hot flashes. I am assuming I am not in that 7% but I am wondering if anyone has read anything about non-hot flash SEs.

sam408 · July 2007

I've been on tamox since March and was having no SEs until this month. My onc said it can take that long to get fully into your system. This month my period stopped, hot flashes started and I have several a day, plus my joints are stiff and achy. I just turned 50 earlier this year.

Good luck,
Sheila

kuchagirl · July 2007

I just learned something new about Tamox: it can take 4 or 5 months for the drug to get fully in your system. Maybe hot flashes are in my future! Now that I've read about the connection between hot flashes & recurrence, I might be happy to get some hot flashes.

Also, I wasn't aware that Tamox can cause increased bruising. I have had at least one unexplained large bruise since I started Tamox (but then again I've been exercising a lot & crashing my bike).

NCbound2009 · July 2007

I also have NO side effects so far...started the med on June 29th..have a follow up with the Onc on the 8th of August.. what do I say...I must be an exception..Im not having side effects except for mild lower back pain which I can handle by walking..or some sort of exercise..I take 10 mg's in the AM and 10 mg's at bedtime..
I posted in another area...I talked to a woman from ACS and she is a 16 yr survivor and also took the Tamoxifen for 5 yrs with NO side effects...so she gave me some hope there..
I hate to stop taking this med if its suppose to help prevent any reacurrance...to tell you the truth I was VERY hesitant on taking it because of the horror stories about it..but got brave and done it..I listen to my body everyday for any different abnormal things..but everything seems so normal..even the fatigue has gone away...
Well guess I will see what the Dr has to say next month..
Rosie

CaliforniaKate · July 2007

kutchagirl, I've been on tamoxifen for 3 1/2 years and am 60, but my blood tests still show I'm still pre-menapausal. I never had hot flashes before my tamoxifen, but did have regular periods. After starting tamoxifen, I had mild hot flashes for a couple months, and since then have been really rare. But I haven't had a period in the past 3 1/2 years. I didn't do chemo, so I figure tamoxifen must be working for me, since it has stopped my periods. I have several friends who have gone thru menapause naturally, and have never had hot flashes. Kate

Zzap · July 2007

I started Tamoxifen in May, and am almost done with my first 90 dose bottle. I've just started getting mild hot flashes this week. Like the others have said, I think it takes a while to fully effect your system. Also, my periods started again after chemo, during radiation, but they've stopped again about a month or so after starting the Tamoxifen (which I started the day after my last rad). It wasn't immediate.

I have noticed that I am bruising more easily than normal. I didn't know that was a SE of Tamoxifen until I read it here in one of these forums. I've learned a ton from the others here. Thanks gals, I really appreciate it!

Harley44 · July 2007

Member,

Hmmm... I guess I have to add yet ANOTHER dr. to my ever growing list! Thanks!

sigh...
HARLEY

scarednancy · July 2007

Hi,
Your symptoms sound like mine. I had two bad weeks of nausea when I started in February and then I had no symptoms at all until a couple of weeks ago when I quit taking Lexapro since I learned on this site that it counteracted the Tamoxifen. Since then I had hot flashes for a week and now I don't have any SE's except I just missed my period. I'm 50 so I would really like that to stop anyway. My oncologist told me that most women have NO se'S with Tamoxifen. He said the small percentage that have bad SE's are just very vocal and talk about it a lot. I just keep riding the BC rollercoaster and hoping for the best. Good luck to all of you!
Nancy

CaliforniaKate · July 2007

It seems like quite a few of us aren't having bad hotflashes with tamoxifen. But now I'm reading at different sites, that this could mean that we aren't metabalising the tamoxifen. I'm really considering paying for the 2D6 genes test on my own, to make sure it is getting into my system. My oncologist says my insurance company won't cover it, and he doesn't seem concerned. But $300 could by me piece of mind, hopefully. I don't want to waste another 1 1/2 years on it if it's not working. Anyone else thinking of doing this? Kate

wallycat · July 2007

Yes, I am going to ask my onco to run the test for me...my insurance will pay, but if they didn't, I would still do it.
$300 is a small price for piece of mind for myself.
If there were no long term side effects from Tamoxifen, I may not care, but there are, so if I don't get benefit I don't want the risk.

san4850 · July 2007

I've been on tamox since May 3, and the only side effects I'm having is feeling flushed. I had a follow up visit recently with the rad. onc. and she noticed that I was perspiring even in air-conditioning. I asked her if this was a hot flash, she said probably. But she did say that hot flashes is a sign that the body is properly metabolizing the drug. I also have had only 1 period since I started on tamox, but other than that I've had no other side effects.

L8895 · July 2007

Many women take Tamoxifen, metabolize it well, and have no side effects.

But if there is a test to show if you are genetically able to metabolize well, why not get it done?

My onc agreed to the test after I brought him several respected articles. (see reference by Wallycat) I actually talked to Dr Matthew Goetz at Mayo, who led one of the studies. He was awesome!

I go to a large oncology/hematology clinic in Minnesota, and they really didn't have much information on this. But they were willing to read the papers I brought, and then agreed to do the test. I was the first one to have the test done from this clinic. But I hope they will do it for many others now. The FDA has actually said they will put information out about this, but are still debating over whether to make the test optional, or recommended.

Turns out I have the genes to be a good metabolizer. Thanks, mom and dad! Yeah.

Do read the info on Tamoxifen and SSRI (anti-depressant/anti-anxiety meds) as some of them are strong inhibitors of Tamoxifen. If you are taking them, you may want to consider switching to a lesser inhibitor.

-Linda

PT63 · July 2007

Hi Everyone
I haven't been on the boards for awhile so I thought I would check in. I also haven't had any side effects on Tamox. except my cycles are much longer (45 days) without any hot flashes etc.
Today was my 6 month check up with my oncologist. I asked her about whether or not a lack of side effects would be a worry. She said absolutely not. Tamoxifen has only been extensively studied in one specific dose. This dose is not based on weight like most medicines are. So it is possible that a smaller, slighter person may have a higher dose per kilo than a larger/ heavier person. This may or may not be why some people are more affected by the dose.
Also, it may have to do with how your body normally reacts to meds. For example, I have very few side effects with any medicine that I have taken, but my sister is sensitive to absolutely everything she takes. So it would be more likely that she would also have more side effects on Tamoxifen.
Of course, this is all speculation with no studies backing it up but it made sense to me. She said that they are currently studying dosages etc. but I didn't ask who is studying it or what dosages.
So I have just decided that this is one thing that I just can't worry about any more.
Just my thoughts
PT

rubytuesday · July 2007

FWIW, I took tamoxifen for 5 years 9 years ago. I didn't have hot flashes. I had very few side effects (dry eyes, short term memory loss, some dizziness). Long story made short, I had a new primary a year ago. When I asked my oncologist about taking Tamoxifen again, his response was: "Why would you want to do that? Tamoxifen failed you.". Since I have read about lack of side effects and Tamoxifen failure, it makes me wonder.

wallycat · July 2007

Rubytuesday,
I'm curious if your tumors were different from one another.
Did you take anything after the Tamoxifen??

PT63, Italians are doing some of the studies with 5 and 10 mg. dosages on the tamoxifen and preliminary results show equal benefits. The old dosage used to be 40mg. and now it is 20mg.

Who knows.
I think if we get cancer we ought to get a crystal ball too!!

Member_of_the_Club · July 2007

How did the tamox fail you? you never saw cancer no. 1 again. That seems like a success to me, though it sucks that you got no. 2.

rubytuesday · July 2007

Wallycat, My tumors were different, the first one was colloid; the second was tubular (actually there were 2 tubular tumors). They were all ER+/PR+. I did not take anything (other than my supplements) after Tamoxifen. BTW, I LOVE the crystal ball idea!!!

MemberoftheClub, I guess my oncologist's take on it was that Tamoxifen is supposed to protect your breasts from future breast cancers both ipsilateral and contralateral and it didn't.

Best wishes!

scarednancy · July 2007

Wow, I've never heard of either of your tumors so I did some research and I find you are very lucky. The prognosis for your types of cancer is much better than for the rest of us, ILC, IDC or IBC. They said yours is very rare. May I ask how you found it and how old you were?

rubytuesday · July 2007

Somehow I didn't feel so lucky when I was diagnosed a second time. LOL...the breast surgeon who did my lumpectomy (1st time around) and did my biopsy this time around said that I intrigue him because I keep developing these rare cancers. GREAT, huh?? When he told me that my latest was even more rare than my first one....welllllll I guess it was good news. He actually said if you are going to have bc, this is the one you want. All of mine were found by 'feel'...the first one I found in the shower (age 43) and the latest was found by my oncologist. NONE of them showed on mammograms and I'm constantly being told that I have VERY dense breasts. Best wishes!

Tamoxifen and NO side effects....worry?

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