Boning Up on Bone Health
Network - Fall 2009
By Robert Gagel, M.D., with Bayan Raji
Contrary to what we’re told as kids, three glasses of milk a day may not be enough to keep our bones strong as we age. Bone health remains an important concern for adults, especially for cancer patients. Some cancer treatments may lead to increased bone loss and some forms of cancer may even stimulate the breakdown of bones, says Robert Gagel, M.D., professor and head of the Division of Internal Medicine.
What causes bones to become weak and brittle?
Calcium is very important for a variety of processes in the body including brain and muscle function. When we don’t take in enough calcium or vitamin D to absorb that calcium in our diet, the body will withdraw it from the skeleton. If unchecked, this will lead to osteoporosis. Bone health is something everyone should be concerned about, but it becomes especially critical for cancer patients whose treatments or disease contribute to these problems.
How are cancer patients categorized by their bone health problems?
Cancer patients who are at risk for issues related to bone health are those who have experienced:
- Breast cancer therapies that lower estrogen levels
- Prostate cancer treated with agents that lower testosterone
- Treatments that use cortisone-like or immunosuppressive agents for patients with cancers such as leukemia and lymphoma
- Cancers such as multiple myeloma that stimulate bone loss and inhibit formation of new bone
Why are women with breast cancer at risk of bone disease like osteoporosis?
Women with breast cancer are usually treated with chemotherapy, which can cause them to develop early menopause. This leads to a deficiency of estrogen that causes bone loss. For a woman who is treated for breast cancer in her 30s or early 40s, it means she experiences bone loss earlier in her life than if she were able to go through menopause naturally.
In addition, the most commonly used breast cancer therapies stop or decrease the production of estrogen by inhibiting the conversion of androgen, normally produced after menopause, to estrogen. Therefore, women with breast cancer have two reasons for developing bone loss — an earlier menopause and therapy for breast cancer that further lowers estrogen levels. Unless treated, this combination will cause great damage to the skeleton.
Do women face more problems related to bone loss than men?
Men with certain types of cancer, such as prostate, also experience bone loss. Therapies that treat prostate cancer lower the levels of testosterone, which prevents bone loss in men. In this instance, men experience bone loss similar to women.
However, men have more bone mass to begin with. It takes longer, on average, for them to reach the level of reduction in bone mass considered to be osteoporosis. Also, men have a shorter life span than women. Therefore, their skeleton may be adequate. As men are living much longer these days, bone loss has become more of an issue and men living into their 80s have as much osteoporosis as women.
How can cancer patients avoid the risk of osteoporosis down the road?
When a patient is diagnosed with cancer, concern about the risk of osteoporosis is probably not the highest priority for the oncologist or the patient. We are trying to build a program in which every patient is evaluated before treatment begins. Right now, it is really up to patients to take the lead. Here are some things people can do:
- Add calcium to your diet — a total of 1,200-1,500 milligrams per day.
- Ask a physician to measure bone density. There is no other way to diagnose osteoporosis.
- Get vitamin D levels checked.
- Exercise — if you don’t use it, you’ll lose it.