How to make the decision to forgo tamoxifen

Cenote17

Basic stats:

Breast cancer left side staged at 1A

Mutation in ATM gene

Lumpectomy, with clean margins, in January 2020

Forewent radiation therapy based on preventative mastectomy scheduled for June 2020

Mastectomy delayed till who-knows-when due to Covid shutting down all non-emergency surgery

Began tamoxifen February 2020

Other medications: Lexapro

Tamoxifen has proved a living nightmare for me. I'm usually an even-keeled person, but now I'm constantly enraged and irritable, to the point where I'm punching myself, breaking things in the house, yelling at colleagues, and threatening my husband with divorce. I literally feel allergic to the world, if that makes sense. Everything makes me mad: forks out of line in the drawer, not able to find the shirt I want in a closet, etc.

I feel like I've gone from a normal person to a completely insane one. My oncologist is useless: try yoga! try acupuncture! she chirps. (As if I could find an acupuncturist in this situation.) She offers no alternatives and just tells me aromatase inhibitors would be even worse. My therapist is nice but doesn't really have any suggestions.

I'm only 51 and I'm supposed to be on this dreadful poison for 10 years. If I go off it, given the genetic defect and the fact that I can't have a mastectomy and it's too late for radiation: yay, I die. But I feel like I'm going to die anyway if I have to stay on this stuff.

Tell me stories of high-risk people who went off tamoxifen? What happened to you/them?

Beesie

Cenote, I'm sorry you are having such a hard time with Tamoxifen.

Given that your diagnosis was Stage IA and that you've already had a lumpectomy with clear margins, at this point, at least within your breast area, you are likely cancer free. So the delay in having the mastectomy is very low risk. And if your plan is to have a bilateral mastectomy, that would significantly reduce your risk to be diagnosed again in the future, which is the risk you face from the ATM gene. This isn't a short-term risk but a longer term one, so here again, the delay in the surgery is not substantially increasing your risk.

The bigger concern is your distant recurrence risk relative to your current diagnosis. Even with a bilateral mastectomy, you would still be prescribed Tamoxifen in order to address this risk. So the question here is whether you had an Oncotype test done. While the Oncotype test results assume that you will be taking Tamoxifen, it's easy to do a reverse calculation to determine what your risk of mets would be if you did not take Tamoxifen. Generally Tamoxifen reduces metastatic risk by 30% - 35%. Based on your Oncotype score, you will better understand how risky it is to not take Tamoxifen. If your Oncotype score was relatively high, then not taking Tamoxifen (and also not having chemo) could put your metastatic risk at a level that leaves you uncomfortable. However if you have a low Oncotype score and therefore a low risk of mets, then this risk might be one that you are comfortable living with. Since you made no mention of chemo, I'm speculating that your risk is not overly high.

I understand your concerns and while your current situation is far from ideal, it is also does not appear to be terribly dire. The concern would be much greater if you had not already had surgery with clear margins, or if your diagnosis was more advanced.

Salamandra

My medical oncologist sang the same song about OS+AI being even worse until I told her that I was coming off the tamoxifen regardless. Then she was all into trying them, and promising that if the side effects were bad I could always stop. But by then she'd thoroughly freaked me out.

I did a bunch of research and decided that there was enough evidence for the efficacy of toremifene (fareston) for me to want to try it as an alternative to tamoxifen. At first she wasn't on board because it's not FDA-approved for premenopausal women and she hasn't seen many patients on it. But I keep pushing and eventually she spoke to her mentor/supervisor and he said that he'd testified to the FDA that it *should* be approved for pre-menopausal women because he agreed that the evidence was sufficient (for a back-up to tamoxifen, not a first line).

Before I got to that point, I had tried lower doses, changing the time of day, splitting the dose, and about 4 different generic brands.

Thankfully toremifene worked out so much better for me side effects-wise than tamoxifen! (my crippling side effect was essentially sedation). If it hadn't, I think I would've tried OS+AI - I'm a bit younger and also watched my mother die of metastatic breast cancer and those were motivating factors - but I'm relieved that that's a bridge I didn't have to cross.

edj3

I tried tamoxifen, had some side effects that greatly interfered with my quality of life and stopped taking the drug. I did have radiation, also a lumpectomy but not an mx. So one more anecdotal point of reference.

Cenote17

This is all very helpful information, and I thank you for it.

My surgeon decided that I didn't need an oncotype. During the lumpectomy, she was not able to detect any cancerous cells at all. Her supposition is that the needle aspiration I'd had done before surgery actually removed the cancerous area. While I still have DCIS, she says, I wasn't given an oncotype. Maybe that means "oncotype 0," but I am not sure.

I'm sure all of us are experiencing the same problem, but it's nearly impossible to send questions of this nature to my oncology team. I'm in a major city (DC) and all the hospitals are almost incommunicado as they prepare for a possible flood of Covid patients. (E.g., oncologists and their nurses at my hospital turned off their message portals and don't respond to voicemails anymore, and they have no publicly accessible email addresses.)

It's possible that I'll just stop tamoxifen until the pandemic retreats enough that regular oncological care will continue. Afterward...well, we'll see what we see? I'd sure like to keep my job/keep my marriage/not get arrested due to the borderline psychosis that tamoxifen has caused for me.

Thanks for your support. This board is a lifeline.

Beesie

That's good information and good news. It sounds as though the size of the invasive cancer was extremely small. This would mean that your risk of a distance recurrence (i.e. mets) is likely very low, which in turn means it's less risky to pass on Tamoxifen.

What do you mean by "While I still have DCIS, she says, I wasn't given an oncotype."? Do you mean that DCIS was all that was found in the surgical pathology, or do you mean that you still have DCIS in the surgical margins?

Not having had the Oncotype test means that you do not have a score - having DCIS only would not mean that your score is 0. There is in fact one Oncotype test for DCIS, which is only used for those who a Stage 0 diagnosis, with pure DCIS and no invasive cancer. The DCIS Oncotype test is used to determine if radiation can be skipped after a lumpectomy for DCIS. Then there is a different Oncotype test for those who have invasive cancer, which is used to determine if the patient would benefit from chemo or if hormone therapy alone would be more appropriate. The invasive cancer Oncotype test is usually only used when an invasive tumor is ER+ and HER2- and is 5mm in size or larger.

If invasive cancer was found in your biopsy, then the DCIS Oncotype test could not be used. And if no invasive cancer was found in your surgical pathology, it's likely that your tumor was considerably smaller than 5mm, so it makes sense then that the invasive cancer Oncotype test wasn't done.