Osteoporosis From Menopause or Breast Cancer Treatment
We generally think of our bones as solid and unchanging, but new bone tissue is always growing and old tissue is always breaking down. Our bodies tend to lose more bone mass than they gain as we get older, and other factors also affect bone health. Breast cancer treatments and menopause can both reduce bone density and lead to osteoporosis and osteopenia.
Osteoporosis is a condition that develops when your body loses too much bone, doesn’t make enough bone, or both. Low bone density makes bones weak and brittle and increases your risk of breaking a bone suddenly and unexpectedly. If you have osteoporosis, it’s possible to break a bone from falling down or even bending over or coughing.
Osteopenia is a condition that develops when you have low bone density and your bones are weaker than they should be. Osteopenia is not as severe as osteoporosis but often leads to osteoporosis if left untreated. The risk of breaking a bone goes up when low bone density progresses from osteopenia to osteoporosis.
Both men and women can develop osteoporosis, but the risk is much higher if you’re a woman who’s gone through menopause. Estrogen levels fall during menopause, which can lead to bone loss. If you’ve been diagnosed with breast cancer, certain breast cancer treatments also can contribute to bone loss.
What causes osteoporosis and osteopenia?
Your bones are constantly renewing themselves. Although bones feel hard, they are living tissue. Each day, your body is making new bone and breaking down old bone. During your childhood and teenage years, your body makes new bone faster than it breaks down old bone and your bone density increases. After your early 20s, this process gradually slows down. As you get older, your body breaks down bone faster than it creates new bone.
In many people, the bones become less dense but bone density remains in the normal range. In other people, bone density becomes lower than normal, which is osteopenia or osteoporosis, depending on how severe the low bone density is. Several factors can increase the risk of these conditions.
Certain breast cancer treatments also can lead to osteopenia and osteoporosis.
There are three aromatase inhibitors that treat breast cancer:
Arimidex (chemical name: anastrozole)
Aromasin (chemical name: exemestane)
Femara (chemical name: letrozole)
All three medicines work by stopping the body from making estrogen, and lower estrogen levels can lead to bone loss.
Some chemotherapy medicines that treat breast cancer can directly affect your bone density. Chemotherapy may cause early menopause, which puts you at higher risk for lower bone density. You also may receive steroids with certain chemotherapy medicines to reduce side effects, and taking steroids can lead to bone loss.
Ovarian shutdown or suppression — either by surgically removing the ovaries or stopping their function with medicine — causes a sudden drop in your body’s estrogen levels, which can lead to lower bone density.
When you go through menopause, your levels of estrogen and other hormones drop sharply. Because estrogen helps maintain bone density, this drop can lead to significant bone loss and, over time, to low bone density, which is osteopenia. If left untreated, this osteopenia can lead to osteoporosis.
You have a higher risk of developing osteopenia and osteoporosis if:
you are a woman — women have less bone tissue, on average, than men
you are a transgender woman receiving certain hormone treatment but not taking estrogen, or who has had gender confirmation surgery with removal of the testicles but is not taking estrogen
you are a transgender man who has not started hormone therapy, who is taking certain types of hormone treatment, or who has had gender confirmation surgery with removal of the ovaries
you are older and have gone through menopause
you have a family history of osteoporosis
you have a small frame
you have overactive thyroid, parathyroid, or adrenal glands
you have a history of weight loss surgery or organ transplant
you have celiac disease or inflammatory bowel disease
you have rheumatoid arthritis
you don’t get enough calcium
you have an eating disorder
you don’t exercise
you have more than two alcoholic drinks per day
you smoke
Listen to the episode of The Breastcancer.org Podcast featuring Dr. Anupama Shahane discussing breast cancer and osteoporosis.
Osteoporosis and osteopenia symptoms
Osteopenia and osteoporosis typically have no symptoms, especially in the early stages. Many people don’t realize they have low bone density until they break a bone. As you get older, it makes sense to watch out for the following signs that could mean you have osteopenia or osteoporosis:
losing an inch or more of height over time
stooping or bending forward
back pain
a bone that breaks much more easily than expected — from bending over or coughing, for example
Understanding bone density
Bone density or bone mineral density is the amount of bone mineral in your bones. Bones containing more minerals are denser, so they tend to be stronger and less likely to break.
Bone density testing
Doctors measure bone mineral density with a DEXA (dual-energy X-ray absorptiometry) scan. Also called a DXA scan, a DEXA scan uses a very small amount of radiation to let doctors see the mineral content of certain bones — such as the hip, spine, and wrist. The scan is quick and painless.
Using a DEXA scan to measure bone mineral density at the hip and spine is considered the most reliable way to diagnose osteoporosis and predict the risk of breaking a bone.
Your DEXA scan results are made up of two scores:
T-score: Your T-score is the difference between your bone density and the average bone density of healthy 25- to 35-year-old adults of your same sex and ethnicity. Most post-menopausal women have a negative number score because their bone density is almost always lower than a 25- to 35-year-old woman. A score of -1 and above is considered normal. A score of between -1 and -2.5 is classified as osteopenia, and a score of -2.5 and below is classified as osteoporosis. The lower the T score, the lower your bone mineral density.
Z-score: Your Z-score is your bone density versus what is considered normal bone density for someone your age, sex, ethnicity, height, and weight. Among older people, low bone mineral density is common, so Z-scores can be misleading.
The National Osteoporosis Foundation recommends you have a DEXA scan if:
you’re a woman age 65 or older
you’re a man age 70 or older
you break a bone after age 50
you’re a post-menopausal woman younger than 65 with risk factors
you’re a man age 50 to 69 with risk factors
It’s important to know that there aren’t official recommendations for bone density testing in transgender women, transgender men, or gender non-conforming people. Still, some medical professionals recommend that regardless of birth-assigned sex:
all transgender people begin bone density screening at age 65
transgender people who have an increased risk for osteoporosis begin screening between the ages of 50 and 64
It’s important to talk to your doctor about your personal risk of osteoporosis and ask when you should start bone mineral testing.
No matter your age, if your breast cancer treatment plan includes therapies that may affect your bone health, you can expect your doctor to recommend:
a baseline DEXA scan before you start treatment
regular DEXA scans during treatment, commonly every two years
The scan results can help you and your doctor make sure your bones stay strong and take immediate steps if your bone density starts to drop.
Treating osteoporosis and osteopenia
Doctors commonly recommend certain lifestyle changes and medicine to treat osteoporosis and osteopenia.
Learn more about treating osteoporosis and osteopenia.
— Last updated on January 23, 2025 at 4:01 PM
