Tamoxifen vs. Raloxifen - For BC Recurrence Risk Management & Bone Health

[TDG]

Just sharing some background before I ask the questions I have about (Selective estrogen receptor modulators = SERMs):

Cancer Profile: Grade 2 IDC, ER8, PR8, 1 positive lymph (out of 25), LVI, PI.
I had a single MX & Axillary Dissection surgery followed by 5 fractions of 26G RT as my primary treatment. No Chemo due to ODX score.

The 5-10 year Endocrine treatment regime I’m on is Letrozole. I have been on it for 8 months and am doing some reading/research on whether to continue with it, or change to a SERM instead. The reason for this is primarily due to concerns around bone health (my baseline DEXA scan highlighted osteopenia) as I already have back and neck pain, secondary concerns around other risks to overall health with oestrogen depletion & thirdly short term joint pain/fatigue side effects of letrozole (AI).

I have spoken to both my GP & Oncologist about what options are available to manage my bone health aside from weight bearing exercises. Both have mentioned Vitamin D & Calcium. I have been taking vitamin D for years so nothing new to change there, and have sufficient calcium in my diet according to a recent calculation I did via an online calculator. I raised the question about Bisphosphonates, it’s not one I was offered as part of oncology treatment as my cancer risk recurrence profile (low ODX score, no chemo) isn’t high enough, I fall under the intermediate risk profile.
My oncologist has previously mentioned Tamoxifen as an alternative, but it also comes with it’s own risk factors (The primary ones I have noted is EC/UC or Endometrial / Uterine Cancer, Blood clots).

I am due to see a Rheumatologist to discuss what would be recommended given above factors. The main bone hardening treatment type I was aware of before was Bishposphonates, but since researching online I’ve recently discovered that there is another drug called Raloxifen (Evista) which is a “SERM” (Selective estrogen receptor modulator) used to reduce the risk of spinal fractures in women after the menopause; Tamoxifen is also a SERM. And upon reading about Raloxifen I see it is also a possible drug for BC recurrence risk management, which does not come with the Uterine Cancer risk that is associated with Tamoxifen. So it appears that Raloxifen could have a dual function for someone who has had BC & is post-menopausal. It’s not a drug that my Oncologist has ever mentioned, and neither has my GP, when discussing bone strength.

So before I see the rheumatologist I’d like to have as much information on hand with me to enable an informative discussion on viable options for managing both bone health, while also managing my breast cancer recurrence risk.

I would like to hear from anyone who has information about this treatment option, or even experience taking it. If anyone else has had a similar discussion with their Oncologist/treatment team, any information/findings you have would be much appreciated.

[MistyK]

Hi TDG

Your post really resonated with me; I had 2 different cancers, one in each breast, ILC and mucinous, both Grade 2, ER8, PR8, 1 node pos (out of 9) which was extracapsular. I had double MX (& Axillary Dissection on left side) followed by 5 fractions of RT (I’m guessing same strength). No chemo as both had low ODX scores (7 and 9). I did, however, develop lymphoedema just 6 weeks after surgery.

I put off the 5-10 year AI treatment (Anastrozole) for 5 months - terrified of the ‘rare’ side effects that posed a risk to eyesight … which, for me, would be unbearable. (Sounds like you did even more research than me!). I endured the ‘routine’ (yeah, right) side effects for 10 months until I lost so much function in my dominant right hand due to the level of joint pain that, with my oncologist’s blessing, I suspended the AI to prove the effects were due to it. They were. After 8 weeks abstinence, I am getting back to my ‘normal’ in various ways.

I’ve also had the first 2 (6-monthly) bisphosphonate infusions. (They come with possible serious side effects too. But, similarly to when AIs were spoken of, potentially life-changing issues were very much played down or skated over. So wrong!) Following the first one: the expected flu symptoms cleared in a week. Following the second one: coincidentally(?) coincided with sudden worsening of all AI side effects. I know many of these can be managed by adding more and more drugs into the mix. I don’t want that.

By whichever method oestrogen is rendered impotent as fuel for cancer growth, it stands to reason that the lack of it impacts the many different processes in the body for which it is vital.

My requested appointment with the NHS oncologist (different to my original one) was postponed, so I saw another privately in the meantime. Like you, I wanted a lot more science, guidance, and debate than is routinely offered. a) I wanted to compare the biological mechanics of how the various AIs and the SERM (also only heard mention of Tamoxifen) worked, and b) I wanted a realistic assessment of my own personal extra risk of recurrence over and above the results that the very basic tool NHS Predict produces (it doesn’t take into account independently the very different subtype that is lobular, nor can it process the instance of having 2 different concurrent breast cancers).

Of the 4 breast cancer consultants I saw (2 x NHS, 2 x private), 1 was really helpful, patient and personable but 3 were arrogant, rather superior beings who most certainly did not appreciate me arriving at the meetings armed with notes, pertinent questions and opinions of my own. (“Someone’s been doing a little too much reading” !!! Well, if they spoke to us properly perhaps we would not feel we had to fumble our own way in the dark. Yes, I’m angry.) As demi-gods, they did not feel they needed to engage in any meaningful discussion with me (and I am not easily put off).

Having more or less decided to waive all adjuvant therapy and take my chances, I just wanted to make sure my understanding of everything was correct and that I was not missing a trick. (There’s nothing ambiguous about Tamoxifen’s common / very common side effects when you look at the NICE website’s info on it. I wonder if Raloxifen avoids all the other Tamoxifen dangers.)

The upshot? I have been left to take a leap of faith unsupported by my ‘team’ (yeah, right. Again.)

I will give it one more go by asking for an NHS consultation in a specialist hospital, making sure they know in advance (so it does not come as an unexpected affront to their status) what I need from them, which is not being patronised and diverted from my quest for answers.

Good luck, TDG, but be prepared for frustration. Keep pushing!
I would love to hear how you go.

[Jolow]

I asked about having raloxifene but was told as i have osteopenia not osteoporosis i could not have it as it is not licensed for breast cancer risk reduction unless i paid for it privately. I was on anastrozle but have a 3rd diagnosis so have been advised to stop and when i get referred to the oncologist discuss medication at that point

[TDG]

@MistyK thank you for replying. Reading your response it sounds like you’ve had a challenging treatment journey with side-effects and I’m sorry to hear about the various other challenges you’ve faced in getting the information you needed.

When it comes to my endocrine treatment journey, I still consider myself at the early stages. I’m learning as I go and have realised that unless you educate yourself with information ahead of an appointment, there really isn’t much to discuss in an informed manner (it’s almost always just listening and asking a few questions). That’s not to say the consultants are willingly holding back information, but rather just giving you the treatment plan they have established is best. I know my circumstances & concerns aren’t necessarily the same as anyone else, so it’s not necessarily possible to compare. I suppose the frustration at times is that there are so many different specialists that need to be involved when there are multiple health issues that crop up & need to be considered when establishing an optimal treatment plan, this cross communication doesn’t necessarily happen unless you personally drive it with some knowledge about what is being said to ask questions. I’m a firm believer in joint decision making and understanding what it is I’m agreeing to or not agreeing to; which I feel sometimes challenges the medical status quo.

If I may, can I ask who prescribed your bisphosphonate treatment, and what type it was? Was it a Zometa (Zoledronic acid) infusion, by your oncologist? The reason I ask is because of the cancer profile you’ve mentioned and as you’ve not mentioned a DEXA scan reflecting ostopenia or osteoporosis? When I asked my oncologist the criteria for that she said it would typically (not necessarily always) be those with a high ODX score (effectively had chemo due to recurrence risk factors), and she said managing/treating bone health outside of BC would be under the remit of my GP, hence why I have spoken to both parties and now due to see a Rheumatologist for advice. My GP did a FRAC score calculation, and mentioned if bisphosphonates were to be prescribed as a GP it would be in tablet form. I didn’t really have much knowledge about types to ask follow-on questions at the time and with brain fog I can’t remember if she mentioned the name of the tablet/drug.

Regarding your question about Raloxifine side-effects, it doesn’t avoid all the side-effects of Tamoxifen. I can’t find the research paper I stumbled upon and read, but what it highlighted was that Raloxifine doesn’t have one of the more serious risk factors (this is my reading of the information I saw published) of Tamoxifen which is Endomertrial / Uterine Cancer. I don’t think I’ve seen any clinical trial papers which had compared the efficacy of T vs R though, but think I did see statements to reflect that Tamoxifen was marginally better. One other key fact I noted about Raloxifine when it comes to osteoporosis prevention, is that its primarily used to reduce the risk of spinal fractures in women who are post-menopausal. So wouldn’t be treatment suitable for just anyone who has ostopenia/osteoporosis.

I can see that Raloxifen is not licensed for BC recurrence risk reduction, but would like to find out if it is licensed for Osteoporosis prevention for anyone with Ostopenia. My thinking there is if you happen to need a SERM for both BC and Osteopenia/Osteoporosis and the bones affected by ostopenia are primarily in your spine, then it may be a viable treatment option instead of Bishphonates.

Unfortunately the reality is that there will be no drug that is free of side-effects, and everyone reacts to them differently, so it’s very much a personal decision. With the analytical mindset I have, I’m willing to try any treatment after understanding/weighing it’s pro’s & con’s compared to alternatives whether that is no treatment or an alternative treatment with a holistic view of my overall health. So the fact finding journey continues.

I will update topic if and when I find out anything new. Wishing you well.

[TDG]

@Jolow, thank you for replying. Regarding the point about licensing, was it your oncologist that mentioned this? And does that mean its only licensed for use if you already have osteoporosis, so effectively meaning it’s not a treatment that an oncologist would prescribe, and something that a GP or Rheumatologist would prescribe for that condition working along side your Oncologist?

Wishing you well, with your ongoing treatment journey. xx

[Jolow]

I believe that is the case. He said he could prescribe it if i had osteoporosis so i guess he could have prescribed it as they can prescribe alendronic acid x

[MistyK]

Hi TDG

Thank you for such a lengthy and considered response to my rant.

‘Analytical mindset’ I understand completely. I did go to these consultations armed with info I’d gleaned and very specific questions (not just a maelstrom of uncertainty) … and it was to exactly that which I found the resistence. It came across as an unwillingness to deviate from the routine received wisdom in order to consider, explore or discuss an alternative view. (Time pressed, as always. Maybe if I’d invited them round for dinner I’d have got a better conversation out of them.)

My original NHS oncologist prescribed the bisphosphonates. (I opted for the 6-monthly zoledronic acid infusions over tablets because the immediate side effects are supposedly short lived.) Part of its recommendation is to offset the bone-weakening effects of the Aromatase Inhibitor, but it also seems to render the bone environment inhospitable to accommodating dormant cancer cells. Although ceasing hormone therapy does not negate all the relevance of zoledronic acid, bisphosphonates still only reduce metastatic breast cancer in bone by around 1%, I believe. In my humble opinion, not enough benefit to risk the possibilty of its more serious long-term side effects.

Some of the common / very common side effects of Tamoxifen listed on NICE in addition to uterine and endometrial cancer are retinopathy, cataracts, cerebral ischaemia (possibly leading to severe/fatal brain injury), embolism, to name just a few. I imagine Raloxifen carries a few or many of the same risks if it works in a similar way, but it does seem to primarily have specific benefits for other issues.

My logical mind says “Cancer recurrence/metastasis is one risk - or 2 risks to be pedantic - albeit up to maybe 30% in my case after 15 years (and this I need explaining more analytically to me, taking into account several anomolies). The treatments, which are not guaranteed to save that from happening anyway, carry several/many serious risks themselves, even if at a far lower percentage for each risk. So 1 risk versus many risks?”

If I’m wrong about anything, then I need someone to disavow me of these assumptions soon!

Do post back with any new findings. Thank you, and good luck with making your choices

[gillid]

I will follow this with interest as i too sm aboutbto request a change. Osteopaenia and 3 pathological.spinal fractures so i am concerned re anastrozole.
I did take anendrolic before my cancer diagnosis but it affected my jaw and i lost bone and an upper front tooth.
So thats not an option.

Bony changes can be slow and i am seriously concerned about fracture risks .

I am tempted to stop treatment but will discuss first.

[TDG]

@gillid, thank you for replying. I hadn’t heard of Alendronic acid until this and have just looked it up now. May I ask whether you had been on this treatment for long (i.e. 2 or more years to enable a repeat DEXA for rechecking bone density) before you developed those side effects? I have not had my rheumatology consultation yet, but will make a note of this particular bisphosphonate in case it is mentioned as an option.

Just sharing the following as an incidental update; I briefly enquired about Raloxifen from another oncologist I met at a BC support group event today who brought up another consideration about the general availability of that drug when compared to Tamoxifen. She also made a few comments to advise that a Rheumatologist wouldn’t necessarily be able to advise on the efficacy of Raloxifen when compared to Tamoxifen for a combination of treating BC and Osteopenia. She did confirm that the Tamoxifen is proven to be beneficial for bone health (supporting bone density) unlike an Aromatise Inhibitor which has the opposite effect.

[gillid]

Hiya, i was on alendronic acid for two years. My repeat DEXA has my bones within normal limits for my age which was great news.
I get awful lower back pain since being on Anastrozole.
I do pilates twice a week. Tai chi and i swim.

It is like playing medical top trumps really. For me id risk the uterine cancer to safe guard my bones i think. I would though like a sensible and impartial conversation about it all.
Hopefully my radiotheraphy appts will come through soon and then i can arrange that.
Im very much my mothers.daughter and age broke so many bones due to her osteoporosis. Her lifestyke was oarticularky healthy though.

Im guessing what we are offered has a lot to do with cost.
I am an ex nurse. I get the pressures in the system but we do have to fight our own corners.

[TDG]

Just posting an update after my consultation in the event it helps anyone else. It was a useful session where I was able to have a dialogue. I did limit my questions to the essentials required due to the time allocated, spending half of it giving a complete picture of my health in summary form. The consultant also corrected some of the information I had misinterpreted in my DEXA report, using the DEXA imaging to explain that my scores weren’t as bad for my age range as I had figured in my mind. It was somewhat educational, which I appreciated.

The discussion regarding Raloxifen was actually quite short as it isn’t prescribed for bone density treatment if you have already had breast cancer (BC). The consultant explained that if I hadn’t had BC then it would have been one treatment option available for me (i.e. under the umbrella of treating Osteopenia/Osteoporosis & preventing BC). I came home and read the information published about it and can see that I missed that nuance when reading it before. Tamoxifen is clearly marked as a drug for treating BC.

He did say that Tamoxifen has sometimes been proven to help with bone density, but that this is not always the case. So even if I switched to that drug for BC prevention, he would recommend checking my bone density in a year after starting it.

He suggested three possible options available to me based on what I told him about recent discussions with my oncologist:
a. I could stay on the AI for BC, then introduce bisphosphonates for bone density, repeat DEXA in 1-2 years time.
b. I could change to tamoxifen for BC, then introduce bishphosphonates for bone density, repeat DEXA in 1-2 years time.
c. I could change to tamoxifen & repeat DEXA in 1 year.

He said I could take a belt and braces approach such as a) or b) or go with c) which would require closer bone density monitoring. All equally valid for consideration.

He didn’t go into discussing the detail of the type of bisphosphonate treatment, but did say there were many forms, he was thinking about an infusion once a year. So not the same as what would be prescribed and given as a BC treatment every 6 months such as Zometa.

I am due to have an MRI to try and help identify the cause for back pain, which he said wouldn’t necessarily be linked to bone density. That was another correction in how my mind automatically tied the two together. Overall a productive consultation, and I’m glad I prepared for it as I did.

[gillid]

Thanks for this update, really interesting. I am hoping to ask for a change to Tamoxifen from Anastrozole. I am getting awful back pain and hip and neck pain too. I know that I have three pathological fractures in my lumbar spine, so bone dentistry is a hot issue for me. To recap,I was on oral bisphosphonates for two years (Alendronic Acid ) and during that time my bone density certainly improved but I lost jaw bone (and a front upper tooth) and the medication was withdrawn. Tamoxifen is thought to have some bone strengthening properties. Anastrozole is certainly known to weaken them. I have been advised to stay on the anastrozole until the completion of radiotherapy in early March and then discuss a change. Its all a bit of a mine field but I absolutely know that i don’t want to live with this gnawing lower back pain indefinitely.
I attend pilates classes twice weekly (have done for six years) and tai chi so am doing what I can to protect myself from further damage. My mother was crippled with osteoporosis, and I am very much her daughter so there are lots of factors to consider. I am also finding the fatigue frustrating now (three months since my diagnosis). Its early days I know but I do need that conversation. To have a summary of yours is really helpful.

[TDG]

I’m glad you’ve found the latest update helpful. Reading the recap you’ve outlined, I see that you’re still in the midst of active treatment for BC, so presume you have not been on Anastrazole (which is another Aromatise Inhibitor like letrozole) for long. Given that your Osteopenia/Osteoporosis diagnosis pre-dates the BC diagnosis do make the BC treatment team aware of that history so that they take it into account when making decisions on endocrine treatment for BC. Sometimes background information does get lost with the NHS healthcare system being fragmented, so it certainly requires the patient to remind or point out health history whether that is family history or personal history.

When I started letrozole, what my oncologist told me about the bone/joint stiffness side effect is that those symptoms do not reflect a loss of bone density. Having done my own reading on the subject I’d agree with that. The rheumatologist I met referred to the side-effect of joint stiffness/pain as arthritic, which I hadn’t really considered at all. Since then I have done a bit of reading on the topic of arthritis and see that there are two types; Osteoarthritis & Rheumatoid arthritis. So if you have experienced joint pain prior to starting Anastrozole, that may well be an independent health issue that warrants a referral to see a rheumatologist for advise. Unpicking the root cause of symptoms can sometimes feel like a bit of a minefield.

As far as bone density goes, you do appear to already have a healthy exercise regime. One aspect I recognised as missing for me after my BC diagnosis was strength / resistance exercises for muscle growth. After my radiotherapy treatment I went on a 12 week exercise programme focussed on strength as it’s known that you loose muscle mass during/after menopause, & we have to work harder at retaining/growing it. The personal trainer also explained to me the importance of muscle for bone health - i.e. the stronger your muscles are the less pressure there will be on your joints. So that may be another exercise category to add, to help with bone health. Just sharing as I have learn’t a lot about the importance of exercise during the past year.

Regarding fatigue, it is still early days but do make sure you make your treatment team aware of how you are feeling. I have ongoing fatigue since treatment finished last July, and am still learning the art of pacing to manage, which is much easier said than done.

I hope you are recovering well from surgery and wish you well for your next leg of treatment. xx

[gillid]

Thankyou so much.
Ive been on anastrozile for three full months.
Ive had a long wait for radiotheraphy ( starts in March) due to pressures on the system.

My lower back issues are arthritic but also due to the fractures. Definately worse since being on this medication, so certainly worth a discussion.
The team are aware of my bone issues but did seem to brush over them i must admit.
Like you, i like to well informed.
The consultant radiologist gave me a booklet on Tamoxifen and certaintly indicated that as more appropriate with my history.
As she said, bony issues often show up many years later.
Ill request a chat with the team right now.
All the best to you

[gillid]

Hello TDG. I thought i would let you know that I had a chat with my surgeon and oncologist, They were very receptive. They agreed that I should stop Anastrazole immediately as my fracture risk is significant. I have been asked to try Tamoxifen as an alternative.

Hope you are doing Ok.

[TDG]

Hi @gillid, apologies for the delayed reply. I’ve had to take a bit of a break from the forum and am just catching up now.

I’m glad to hear you’ve had that conversation with your team, and that they were receptive to hearing your concerns. I’d be interested in hearing how you get on with Tamoxifen both from a BC and bone health perspective as I think I will be on the same soon.

As for me, I’m still on a medication break (letrazole) which was extended beyond the initially planned 6 weeks due some unplanned travel I’ve had to support family with a medical emergency. It’s now approximately 8 weeks since I started my break and am due to see my oncologist next week to discuss starting Tamoxifen. On the note of letrazole joint related side effects I still have stiffness in my knuckles (primarily my right hand & knees when I remain still for long periods of time) but most others seem to have receded, so for me it appears that it will take a while for those side effects to clear. I had to reschedule all appointments including my gynaecology one to the coming week, due to the unexpected travel I’ve had over the last few weeks. I also need to get an appointment in to check my eyes ahead of starting tamoxifen. I’m doing both of these to understand my baseline uterine (Endometrial cancer risk) and sight (cataract risk) health as these are the tamoxifen risk factors I feel I can try to make informed choices about in some small way by knowing where I stand today.

I’ve also seen my rheumatologist to discuss what if anything was found in the MRI that was done on my neck & spine. Nothing sinister was found other than bad posture being the most likely cause of my back and neck pain, so physiotherapy has been recommended. I’m glad I had it done, as it ruled various thoughts that were running around in my mind since my BC diagnosis. This time around my rheumatologist did say I could ask my oncologist about raloxifene to see what they recommended from a BC perspective, so I plan to ask that when I go next week, purely from a educational perspective before I commence tamoxifen.

I will post an update here, if I find out anything new. Take care.

[gillid]

Good to hear from you. Sounds like you have had a lot on. I hope that all that trauma has settled down for you. In truth my consultant did very much infer that he has a pathway to follow and he would be negligent not to follow it. He indicated that the medication doesn’t make a massive difference statistically and that if I struggle with the Tamoxifen he would understand if I stopped it. That would be MY decision and not his if you get my drift. he would have fulfilled his brief so to speak. It is all a rather uncertain journey into the unknown.
My oncologist , however, was clear that Tamoxifen was the way for ward for me and an important part of my recovery. So I have started it…