Breast Cancer and Osteoporosis: Risks and Management

Some cancer treatments increase osteoporosis risk

Ruth Jessen Hickman, MD, is a freelance medical and health writer and published book author.

Archana Sharma, DO, is board certified in General Pediatrics and Pediatric Hematology/Oncology.

Breast cancer and osteoporosis are both relatively common health conditions in women, whose risk for both conditions increases as they age. Many breast cancer treatments contribute to the development of osteoporosis, affecting bone health and potentially leading to serious fractures.

This article discusses the connection between breast cancer and osteoporosis, associated risks, and ways to decrease them.

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Because both breast cancer and osteoporosis are common in postmenopausal women, it's not surprising that many women who have had breast cancer also develop osteoporosis.

However, women who have had breast cancer are at a greater risk of osteoporosis than women who haven't had breast cancer. Scientists believe this is due to the way some breast cancer treatments affect and weaken the bones.

It's estimated that up to 80% of breast cancer patients experience some degree of bone loss due to their treatment history.

Women with breast cancer also seem to have a higher risk of fractures than women without breast cancer and an increased risk for more severe osteoporosis.

Unfortunately, many women with breast cancer don't know that they have an increased risk of osteoporosis and don't realize there are ways to help prevent it.

Breast cancer generally increases the risk of osteoporosis, but women with estrogen receptor-positive breast cancer have an even greater risk of developing osteoporosis. This is likely due to the cancer treatments required for this disease.

Aromatase inhibitor drugs, such as Femara (letrozole) and Arimidex (anastrozole), are standard treatments for most postmenopausal women with estrogen receptor-positive breast cancer. These drugs lower the active estrogen in the body, which helps treat cancer.

But the cells inside your bones also have estrogen receptors to help maintain bone mass. Taking aromatase inhibitors blocks estrogen signaling in your bones, which can increase your risk of osteoporosis. These drugs can be taken for years to help treat breast cancer or prevent recurrence and can significantly impact bone health over time.

Other breast cancer treatments that may increase the risk of osteoporosis include:

The risks of some breast cancer therapies are unclear. For example, Soltamox (tamoxifen) may decrease the risk of osteoporosis when taken after menopause but increase it when taken before.

Treating and managing breast cancer and osteoporosis will depend on your breast cancer type, the severity of breast cancer and/or osteoporosis, your age, other medical issues and risk factors you may have, and personal preferences.

Some women have preexisting osteoporosis before starting treatment, while others may have issues with bone health during or after it's complete. Breast cancer treatment takes priority over osteoporosis treatment, even if it slightly increases your risk of osteoporosis later.

However, speak to your healthcare provider early to determine the best breast cancer treatment for you.

Lifestyle changes, medication, and preventive bone scans can all help prevent osteoporosis.

Although certain risk factors for osteoporosis cannot be changed, like age, sex, or history of breast cancer treatment, you can make lifestyle choices to help decrease your risk. Quitting smoking, drinking moderately (or abstaining), and getting enough exercise can help.

Getting enough calcium and vitamin D to help maximize your bone strength is also essential. Your healthcare provider can help you determine levels and suggest supplements or dietary changes if you aren't getting enough of these nutrients.

The American Cancer Society recommends that all postmenopausal breast cancer survivors get a DEXA scan, which measures bone density. The following groups of women with breast cancer should also get scans every two years:

In general, the National Osteoporosis Foundation recommends bone mineral density testing in women 65 and older and in women 50 years or older with multiple risk factors for osteoporosis, such as breast cancer.

Some women benefit from medications to help build bone strength and prevent osteoporotic fractures and may be a good option if you have a moderate or high fracture risk.

Several of these medications include:

Another option may be selective estrogen receptor modulators (SERMs). This group of drugs, including Evista (raloxifene), is sometimes prescribed to help prevent osteoporosis. However, these drugs may also help prevent breast cancer for those with higher risk. It's unclear of their benefit, however, if you've already had breast cancer.

Some evidence also suggests that bisphosphonate drugs given for osteoporosis might also help prevent cancer recurrence in the bone, at least in postmenopausal women at the start of treatment.

Osteoporosis and breast cancer are relatively common conditions in women, especially after menopause. Many women will experience both health issues just by chance. However, getting breast cancer increases your risk of osteoporosis and of breaking a bone, likely due to the effects of breast cancer treatments.

Lifestyle changes, such as quitting smoking, exercising, and getting more calcium and vitamin D, can help prevent osteoporosis. For some breast cancer survivors, taking medications to treat osteoporosis and help prevent fractures is a good option. Speak with your healthcare provider to determine an individualized treatment plan that works for you.

If you’ve just been diagnosed with breast cancer, osteoporosis is probably not in the forefront of your mind. Understandably, you’ll want to focus on your cancer treatment.

But with more people now living for many years after their initial diagnosis, you’ll eventually want to consider your long-term health needs. Don't hesitate to talk to your healthcare provider about getting assessed for osteoporosis and starting treatment if you need it.

Yes, it can. Depending on the breast cancer treatment you receive, you may be at an increased risk for osteoporosis. However, other factors also affect your osteoporosis risk. Talk with your healthcare provider about the best ways to monitor your bone health and help prevent fractures.

No. Scientists have not discovered such a link.

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By Ruth Jessen Hickman, MDRuth Jessen Hickman, MD, is a freelance medical and health writer and published book author.