What You Should Know About Bone Health When It Comes To Breast Cancer Treatments

When undergoing breast cancer treatments, many factors need to be considered. While certain things may be obvious, others may not be as clear; however, bone health is a factor that should be top-of-mind when undergoing your breast cancer treatment journey.

Read on to learn about breast cancer treatments, how they may contribute to bone weakening and what you can do about it.


Chemotherapy is a common treatment for breast cancer, and while many women find success with this treatment, they may experience a lower bone mineral density once treatment is complete. This is likely due to the effects chemotherapy may have on the ovaries and organs that produce estrogen. Chemotherapy has been associated with ovarian dysfunction, and thus, onset of menopause has been shown to arrive earlier in pre-menopausal women who received chemotherapy treatments. What this is that early onset of menopause can cause reduced estrogen levels, which leads to an increase in bone breakdown resulting in the loss of bone density.

Ovarian Suppression

Ovarian suppression is a treatment option that has been used for many years, and involves removing or temporarily stopping the ovaries from working. When ovaries are not working efficiently, estrogen is not being secreted, and thus bones may break down at a faster rate than how they are being built.

Anti-estrogen therapies: Aromatase inhibitors and Tamoxifen

Antiestrogen therapies block hormone actions or lower hormone levels in the body. Two such therapies, aromatase inhibitors and tamoxifen, have specifically been shown to negatively affect bone health in women. 

Aromatase inhibitors (such as anastrozoleletrozole and exemestane) while they bring myriad of treatment benefits and can increase patient outcome, they also reduce the amount of estrogen in the body, thus reducing bone density. Since these drugs block the conversion of androgen to estrogen, estrogen levels in the body are decreased. As mentioned previously, lower estrogen levels often mean reduced bone mineral density. In the case of aromatase inhibitor use, it has been reported that bone fracture risk is increased, and bone loss is accelerated.

Tamoxifen is another anti-estrogen therapy that blocks estrogen from attaching to hormone receptors. Since breast cancer cells need estrogen hormones to grow, this obstruction helps slow or stop the growth of the cancer in certain cases. The effects tamoxifen has on bone health depends on whether a woman is premenopausal or postmenopausal, as data suggests this drug has an opposite effect depending on the stage of life. In postmenopausal women, tamoxifen appears to protect against bone loss,while it appears to decrease bone mineral density in premenopausal women.


Radiation therapy is a treatment that utilizes high doses or radiation directly onto the tumor. Using radiation therapy has the potential to take a toll on bone health, damaging soft-tissue components of the bone, including blood vessels. Radiation may lead to bone loss in the area where radiation therapy was given, as well as an increased risk of fracture

Bone Loss Prevention Therapies

Bone loss prevention therapies have proven nearly universally effective for limiting bone loss in cancer patients.

Some examples of breast cancer treatments that don’t cause bone loss are as follows:

  • Immunotherapy, which helps the immune system identify and more effectively eliminate cancer cells.
  • Denosumab (Prolia/Xgeva) are a group of drugs that are used to prevent or treat bone problems. It has been shown to increase bone mass in certain cases.
  • Biophosphates are drugs that prevent the loss of bone density. They are the most commonly prescribed drugs used to treat osteoporosis. Zoledronic acid (Reclast/Zometa) is a type of biophosphate that reduces the amount of calcium released from bones into blood. It also works by slowing the breakdown of your bones by cancer to prevent bone fractures.

Note that certain side effects may occur, such as osteonecrosis of the jaw (when the jaw bone is exposed and begins to starve from a lack of blood) and hypocalcemia (low blood calcium levels).

What You Can Do To Love Your Bones When Undergoing Breast Cancer Treatment

While certain common breast cancer treatments have been shown to result in positive outcomes, unfortunately many come with the side-effect of taking a toll on bone health.

To combat these effects, it is wise to support bone health before and during treatment is started (if possible) to maximize bone density when possible. This includes steps like:

  • Consuming adequate calcium, magnesium, vitamin D, phosphorus, protein, and other bone-building nutrients
  • Limiting or avoiding alcohol
  • Drinking at least 8 glasses of water per day
  • Participating in weight-bearing exercise
  • Avoiding cigarette smoking
  • Reducing caffeine intake
  • Healthy diet, exercise lifestyle choices
  • Good sleeping habits and reducing stress

Supporting bone health before, during, and after treatment is a wise step to reduce your risk of struggling with bone health issues later in life, like fractures or an osteoporosis diagnosis. Simple steps can have a large impact when it comes to bone health. 

Our next article speaks on bone disease, and how you can be empowered regardless of your diagnosis.