OSTEOPOROSIS

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.

Breast cancer treatments

Certain breast cancer treatments also can lead to osteopenia and osteoporosis.

Aromatase inhibitors

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.

Chemotherapy

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

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.

Menopause (post-menopausal osteoporosis)

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.

Other risk factors

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

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.

Treatments

Doctors commonly recommend certain lifestyle changes and medicine to treat osteoporosis and osteopenia.

Lifestyle changes to treat osteoporosis and osteopenia

Get enough calcium. The amount of calcium you need depends on your age and sex assigned at birth:

women and men age 19 to 50 need 1,000 milligrams a day
women age 51 to 70 need 1,200 milligrams a day
men age 51 to 70 need 1,000 milligrams a day
women and men age 71 and older need 1,200 milligrams a day

Food, rather than supplements, is the best source of calcium. Dairy products, including milk, cheese, and yogurt, are high in calcium. Other good sources are:

salmon with bones
sardines
kale
broccoli
calcium-fortified juices and breads
dried figs

If it’s difficult for you to get enough calcium from food, you may want to ask your doctor about taking a calcium supplement.

Get enough vitamin D. Vitamin D helps your body absorb calcium. You can get some vitamin D from being in sunlight. The amount of vitamin D you need depends on a number of factors, including:

age
ethnicity
the latitude at which you live
the season of the year
how much sun exposure you get

The National Institutes of Health recommend adults age 19 to 70 get 600 IU (international units) per day and adults age 71 and older get 800 IU per day. Still, if you have darker skin or get very little sun exposure, you may need more vitamin D a day, either from food or from a supplement.

Foods rich in vitamin D:

vitamin D-fortified milks and cereals
wild-caught fatty fish such as salmon, tuna, and mackerel
cod liver oil

If you take a vitamin D supplement, most experts recommend taking the D3 (cholecalciferol) form rather than the D2 (ergocalciferol) form.

Because vitamin D is a fat-soluble vitamin, your body absorbs it best when you take the supplement with a meal or snack that includes some fat.

East more prunes. A study found that eating prunes every day can help preserve bone density.

Exercise Regularly

Weight-bearing and muscle-strengthening exercises help you build and maintain bone density and can help your bones stay healthy throughout your life. Balance exercises can help reduce your risk of falling, especially as you get older. It’s a good idea to try doing a combination of weight-bearing and muscle-strengthening exercises for at least 30 minutes a day. You also can try doing weight-bearing and muscle-strengthening exercises one day, and balance exercises the next.

Limit or avoid alcohol. Research shows that heavy drinking dramatically affects bone health and increases the risk of osteoporosis.

Don’t smoke, or quit if you do. Tobacco use weakens bones.

When deciding which osteoporosis medicine to recommend, your doctor has to consider a number of factors, including:

Your sex assigned at birth: Some medicines are approved for both women and men and some are approved for women only.
Your age: Some medicines are best for younger post-menopausal women and others are best for older women.
Your bone density: Different osteoporosis medicines work in different ways. Medicine for someone with extremely low bone density or who has broken multiple bones, is different from medicine for someone with bone density that’s just a bit lower than normal.
Other health conditions you may have: If you’ve been diagnosed with breast cancer, you should not take osteoporosis medicines that contain estrogen.
Your preferences: It may be easier for you to receive an injection once a month or once a year than to take a pill every day.

Medications

Bisphosphonates

Bisphosphonates limit the activity of certain bone cells, called osteoclasts, which break down and reabsorb minerals such as calcium from bones. Limiting the osteoclasts allows the osteoblasts — the bone-building cells — to work more effectively. Bisphosphonates that treat osteoporosis are:

alendronate (brand names: Fosamax, Binosto): available as a tablet or liquid, in doses taken daily or weekly
risedronate (brand names: Actonel, Atelvia): available as a tablet, in doses taken daily, weekly, monthly, or twice a month
ibandronate (brand name: Boniva): available as a tablet taken monthly or as an injection every three months
zoledronic acid (brand name: Reclast): available as an IV infusion once a year or once every two years

People must take oral bisphosphonates in the form of tablets or liquid in a specific way to avoid serious harm to the esophagus (the passageway between the mouth and the stomach):

You take a bisphosphonate with six to eight ounces of plain or tap water on an empty stomach at least 30 minutes (for alendronate and risedronate) or 60 minutes (for ibandronate) before your first food or beverage of the day.
You can’t lie down for at least 30 minutes (for alendronate and risedronate) or 60 minutes (for ibandronate) after you take the bisphosphonate.
You must wait 30 minutes (for alendronate and risedronate) or 60 minutes (for ibandronate) after you take the bisphosphonate before you eat, drink (except for plain water), or take other medicines.

It’s important to know that the zoledronic acid IV infusion may cause serious kidney problems. Kidney problems after a zoledronic acid infusion are more likely in people who:

have existing kidney problems
take a diuretic (a medicine that removes water from the body)
are dehydrated when they receive the infusion or become dehydrated afterward
take other medicines that can cause kidney problems
are older

You should drink at least two glasses of water within a few hours of receiving a zoledronic acid infusion.

The bisphosphonates also may cause rare but serious side effects:

Atypical femur fracture. The femur is the large leg bone that runs from your hip to your knee. An atypical fracture means that the bone breaks in an uncommon spot. Although research suggests the risk of an atypical femur fracture goes up the longer you take a bisphosphonate, these fractures are rare.
Osteonecrosis of the jaw. A condition in which the cells in the jaw bone start to die.

SERM (selective estrogen receptor modulator)

Evista (chemical name: raloxifene) is a SERM used to:

reduce the risk of hormone receptor-positive breast cancer if you’re post-menopausal and receiving treatment for osteoporosis but haven’t been diagnosed with breast cancer
treat and reduce the risk of osteoporosis if you’re post-menopausal

Targeted therapy

Prolia (chemical name: denosumab) is a type of targeted therapy called a RANKL inhibitor. Like the bisphosphonates, RANKL inhibitors limit the activity of osteoclasts, which break down and reabsorb minerals such as calcium from bones. Limiting the osteoclasts allows the osteoblasts — the bone-building cells — to work more effectively.

Prolia is used to:

treat osteoporosis in post-menopausal women with a high risk of breaking a bone
increase bone density in women with a high risk of breaking a bone who are taking an aromatase inhibitor after surgery for early-stage breast cancer
treat osteoporosis caused by steroid treatment in women and men with a high risk of breaking a bone
treat osteoporosis in men with a high risk of breaking a bone
increase bone density in men with a high risk of breaking a bone who are being treated with hormonal therapy for stage I to stage III prostate cancer

Prolia is given as an injection under the skin of the upper arm, upper thigh, or abdomen every six months.

Under the brand name Xgeva, denosumab is used to reduce the risk of bone complications and bone pain in people diagnosed with metastatic breast cancer that has spread to the bones.

There are several Prolia biosimilars approved by the U.S. Food and Drug Administration: Bildyos (chemical name: denosumab-nxxp), Boncresa (chemical name: denosumab-mobz), Bosaya (chemical name: denosumab-kyqq), Enoby (chemical name: denosumad-qbde), Jubbonti (chemical name: denosumab-bddz), Stoboclo (chemical name: denosumab-bmwo), and Ponlimsi (chemical name: denosumab-adet).

Like many medicines, Prolia may cause side effects, some of them serious. Rare but serious side effects include:

Atypical femur fracture.
Osteonecrosis of the jaw.
Extremely low blood calcium levels. Your doctor monitors your calcium and vitamin D levels while you’re receiving Prolia.
Infection, especially skin infections. Tell your doctor right away if you notice any signs of infection, especially redness, swelling, and painful areas on your skin.
Rash. Let your doctor know if you develop any type of scaly, itchy, or red patches on your skin.
Bone and joint pain. Prolia may cause severe bone, joint, or muscle pain.

Tell your doctor if you have any of these side effects.