The Devil and the Details
Today was a four month visit with my oncologist after my second diagnosis of breast cancer one year ago. One of the purposes of the visit was to discuss bone loss while on Arimidex, the Aromatase Inhibitor I will be taking for ten years, unless of course they come up with something new between now and then.
I was diagnosed with both invasive and in situ lobular carcinoma (LCIS) in my left breast twelve years ago. After two lumpectomies to achieve clear margins, eighteen weeks of chemotherapy and six weeks of daily radiation I took Tamoxifen for five years.
Last year I had a recurrence of LCIS in the left breast and a new and different cancer, ductal carcinoma in situ (DCIS), in the right breast. Because of the new cancer in the right breast and the fact I had a recurrence in the left breast I had a double mastectomy. I was then prescribed Arimidex, the aromatase inhibitor (AI), to be taken for a ten year period.
The type of cancer I had was estrogen receptor positive (ER+). Postmenopausal women are given AI’s to stop the production of estrogen. Estrogen stimulates the growth of ER+ cancer so “inhibiting” the production by taking the AI translates into less estrogen to fuel cancer cells from developing. I think of it in simplest form like an equation:
“ER+” cancer + AI = Less/suppressed cancer growth
My Take Away and Understanding
One of the side effects of taking an AI, because it inhibits the production of estrogen, is bone loss. It is very important to monitor bone density while taking an AI. I learned today about the difference between osteoclasts and osteoblasts. This was my take away after listening to the explanation given to me by my oncologist.
Keeping the Balance
Bones are living organisms and like the rest of your body work to maintain balance. Osteoclasts work at resorption, or the breaking down of bones. Osteoblasts build bones or form new bone cells. I just remembered the “b” in Osteoblasts. B = building. So it makes sense that the balance is disrupted when estrogen is depleted and bone loss occurs…. Osteoclasts tend to outnumber the osteoblasts in osteoporosis, in laymen terms.
I will be taking a product called Prolia to build up more of those Osteoblasts and maintain that all important balance. While this was being explained to me I couldn’t help wonder how in the heck you monitor the balance. That is why a DXA scan or bone density test is an important part of the monitoring process. If you have too many osteoblasts your bones can become so hard, so dense, that this can produce a fracture as easy as having thin bones. The way it was explained to me, and quite frankly made sense, is that if something is very dense, dropping or jarring it can make it crack just as much as if it were of thin makeup.
Our bodies are such complex systems and maintaining the balance is so important. I really wasn’t looking forward to more “chemicals”, more “stuff” in my body but I certainly see the value in this medication, especially with a family history of osteoporosis aside from my cancer diagnosis. My oncologist explained all the possible side effects as well as the monitoring mechanisms that will be in place to maintain that balance.
A Real Shot in the Arm!
Prolia will be given to me in shot form, subcutaneous (below the skin), twice a year. There is no perfect predictor as to how long I will take it other than monitoring my bone density through the DXA. Each person is individual so when I reach a point that my bones are in balance then I will stop the injections so as not to “overproduce” those osteoblasts.
The Bare-bones Definition
Keep in mind this is the interpretation and take away I got from the explanation I was given. As an educator, I know we all absorb information and process it in different ways but I hope that this helps the reader understand in simplest form the importance of talking to your health care provider about this type of medication if you are on an AI for a diagnosis of ER+ cancer and there might be a family history of osteoporosis. The side effects can be found in the brochure that your health care provider gives you or on the product website. I wanted to provide a simple explanation of the mechanics of bone cell production, loss and maintaining the balance.
Hi Terri,
Thank you for this helpful info on AIs and bone loss. This is such an important issue for many of us, me included. My bone health took a hit while on Arimidex. I went off of it due to problems tolerating it and I’m now on a different AI. We are monitoring things closely. I’m not sure I’ve heard about Prolia, so I might have to look more into it. Just curious, how often will you be having bone density tests? If you care to share of course.
Thanks again for the informative post.
Of course, sharing is caring. I think the bone density is pending approval from insurance. Normally it is every two years. However, I had one a year ago BEFORE the 2nd BC Dx. If approved, I will get another one early Fall since I have been on the AI for a year now. I am sorry to hear about your bone loss as well as not tolerating the Arimidex. Monitoring things closely is always key to all BC patients. I think this is part of our “blog mission”, if you will, to educate, inform and let others now that you can be a good self-advocate. Let me know what you find out about Prolia. Let’s share and compare our information. Wishing you a restful weekend, Nancy, and it’s always good to hear from you.
Great post. I am dragging my feet on the switch from Tamoxifen to AI for this very reason
Hi Uzma,
Thanks for the thoughts on the post. Yes, all these tough decisions we make based on informed decisions are not always easy. I did Tamoxifen 12 years ago and now the AI. I think it is so important to maintain a healthy lifestyle with the foods you eat and the exercise you do. Even at that, it doesn’t stop the side effects. However, I do believe it helps keep you stronger and perhaps able to deal with side effects better. Maybe it’s just a mental thing for me knowing I’m doing what I can to stay stronger through all the hits we get with this disease and all that comes with it. Cheers!
Terri, thank you for sharing this information. I have a family history of osteoporosis as well, but back when I was first treated, I took tamoxifen instead of AIs, because of the threat of bone loss with the latter. I hope the prolia works. I wish they would come up with more SERMs that have fewer side effects than tamoxifen and more effectiveness. Or just a better, more targeted way to deal with ER+ breast cancer than effectively destroying all the estrogen in our whole bodies.
Hi Kathi,
First of all, I love your webpage and the red “slippers”…. a woman after my own Irish heart with that Celtic symbol. 🙂
I hope the Prolia works, too. There is always the “side effect what ifs” in the back of your mind. Close monitoring is going to be the key. I really need to start focusing on some added weight training as well. I did a lot of it, 3-4 x/week, before my reconstruction surgery. I’m working on gaining back my balance and strength now that I am finished with both phases. The climb back, ARGH! I hope they continue to explore the SERMs as well. I have been on the AI for a year. Aside from an occasional hot flash I haven’t had the side effects that some have experienced and hope it continues that way.
The shared information is what keeps us all in the loop so I appreciate the comment. Thanks so much.