Let me explain. No, there is too much. Let me sum up.

In looking back over my posts, I neglected to mention a couple of things about my bones.

First, I had all those tests run last July and as my endocrinologist thought, everything is great. So that means I don’t have an underlying reason for the bone issue. He recommended Prolia which is given once every six months by injection. I had the first injection in September with no issues.

In March, right as everything was getting locked down from COVID, I had the second injection. And the next day I had an allergic reaction around the injection site. It looked a lot like hives. Kent pushed me to get it checked out, although I didn't want to. So I compromised by calling the online nurse through my insurance company. Based on what I shared with that nurse, he recommended I get seen at Urgent Care so I did and sure enough. It was an allergic reaction.

Here’s the thing. I did a little research online and it turns out the housing mechanism Prolia comes in contains natural rubber which is closely related to latex  (see page 4, section 2.3 in this PDF). And I have a latex allergy. Apparently that was enough for me to have that reaction. So Prolia is off the table.

Today he and I talked through my options and there aren’t a lot. My number one goal is to stop breaking bones while running. So the treatment options are a drug that’s injected every day or one that’s given by infusion once a year. After talking through the pros and cons, I’ll be trying one of the daily injections.

He gave me a sample of Tymlos and recommended a trial run to make sure I don’t have an allergic reaction. Assuming I don’t, I’ll get started with the daily injections in September.

What cracked me up is this case he also gave me. It's actually for the other daily injection drug, Forteo (he didn't have any samples of that one). It’s made by Vera Bradley. I don’t know why that tickles me so much, after all Delta’s first-class amenities bag on international flights is by Tumi so it’s the same sort of thing. It just seems different for drugs.

Five needles per bag,
and there are six bags.

Designer baybee!

About those side effects

I’m on week four of tamoxifen (with another four years, 48 weeks in front of me if taken as planned). I’m taking just a quarter dose of what’s normally prescribed, and that’s on purpose. I haven’t had good experiences with drugs that interfere with hormones and hoped that a slow ramp up to the full 20 mg would mitigate any side effects.

Unfortunately that’s not what’s going on. This whole thing is further complicated by me starting Prolia 10 days before starting tamoxifen so teasing apart what’s causing what is a little difficult. Both drugs can cause muscle pain, joint pain and bone pain, all of which I have. But those didn’t start until about day 10 of the tamoxifen which is also when I noticed my heart rate getting too high while running (another tamoxifen side effect although apparently not very common) and also started having serious hot flashes.

I didn’t have hot flashes in menopause, I had more what I’d call warm flashes. But these are much more intense—sweat rolls down my face, I’ve soaked my clothes. They’re pretty intense.

But it’s the heart rate issue that concerns me the most because it’s affecting my runs. It’s not safe for me to run at my maximum heart rate for very long (it’s not good for anyone, not just me) and it’s been spiking that high a lot. Sunday’s “run” was mostly walking because my heart rate wouldn’t stay down.

I run because I love it, sure. But running also plays an important role in reducing my risk of this breast cancer recurring.  According to this study (summarized in this article), physical activity can reduce the risk of death from breast cancer by about 40%.

But what’s my risk?

I used this online calculator to run my results two different ways. The pathology report from my biopsy said that lymphovascular invasion was present, and the path report from my lumpectomy said it was absent.

Including the LVI, I have an 18% risk of recurrence in the next 15 years. When I reran the test using no LVI present, my risk is 11%.

Here are two more results using a different calculator, one with me taking tamoxifen and one without.

Taking tamoxifen

No tamoxifen

Let’s go with the worst-case scenario. If I have an 18% risk of death specific to breast cancer in the next 15 years, and I continue working out the way I normally do then my risk drops to 10.2%. Sure I could cut that 18% risk by 1/3 by taking tamoxifen but at this rate, I would lose the benefit from exercise.

As I told Kent, I don’t have a death wish, I have a life fully lived wish. I’ve scouted around the forums that have been so helpful to me and magnesium glycinate has helped others with the same sorts of side effects. I got some last night and started taking it. I’ll give the tamoxifen + magnesium at least a week. If things aren’t better, I’ll stop the tamoxifen and continue the magnesium by itself for a couple of weeks and then try again with the tamoxifen.

Tomorrow is D Day

In April, when I was diagnosed with breast cancer, my medical oncologist laid out his preferred plan of treatment after I’d had surgery and radiation. Because I’d been diagnosed with osteopenia (later changed to osteoporosis by my endocrinologist), aromatase inhibitors were off the table. They weaken bones and mine are already compromised. So instead, he told me I would be taking tamoxifen, 20 mg a day for probably five years, maybe more.

I'm not at all excited about taking tamoxifen. It's got some well-known common side effects that would greatly interfere with activities I enjoy. I'm not sure how much I'm willing to tolerate there, to be honest, especially since tamoxifen reduces the risk of cancer recurring by less than 10% for me. Diet and exercise give me far more bang for the buck with a 40% reduction in risk. Still, I'm not as low risk as I would have hoped, and one of the pathology reports indicated I had some lymphovascular invasion. That isn't necessarily a sign that this cancer will return or metastasize some place else but it's something to keep in mind.

So I’ve wrestled with whether I’m up for going on this drug. And as I told my MO, I had already signed up for a 10K race—the Plaza 10K which was two weeks ago—and I didn’t want to go on anything until after that race.

He agreed to that delay, which of course I’ve scope creeped by adding in two more 10K races, which were all part of the Heartland 30K Challenge (you can read about the Challenge here and I'll write more about those races later this week). And in the meantime, I ended up going on Prolia a week ago last Friday. Again, I would have preferred to start that drug after these three races were over, but my hip hurts all the time where I broke it and I’m highly, highly motivated to save my bones from something I clearly have.

In the last 10 days, I’ve unfortunately experienced some side effects from Prolia. That’s a little discouraging to be honest. Joint pain where I’ve never had any joint pain, muscle pain too, dry mouth—nothing major but still annoying. But at least I know what the Prolia feels like on its own.

And now tomorrow I guess I’ll find out what the tamoxifen feels like. I’m doing the slowest ramp up in the world—I’m starting with 5 mg a day and I’ll see how that feels. If I’m lucky and don’t have any side effects, I’ll go to 10 mg. But slow and steady is my motto on this part of my cancer treatment.

Bought a fancy pants pill splitter just for this drug.