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Cancer patients and survivors may be at increased risk of bone fractures. Studies have shown, for example, that
breast cancer survivors tend to have lower bone density compared to healthy women. In addition, a recent study
sponsored in part by the National Institute of Arthritis and Musculoskeletal and Skin Diseases found that breast
cancer survivors may be at an increased risk for bone fractures. This may be because some breast cancer treatments
may weaken bones. Being diagnosed and treated with cancer can also lead to physical inactivity, which puts women
at greater risk of fracture.
Chemotherapy can sometimes put a woman into early menopause, which causes estrogen levels in her body
to decline. When estrogen levels decline, women are at increased risk of osteoporosis-a bone-thinning
disease that can lead to an increase risk of bone fractures. Early menopause does not occur in all
women undergoing chemotherapy, and is more likely in women approaching the age of menopause (average age is around 50).
Other cancer treatments, such as some hormonal therapies, can also affect the bone-in some cases, making
the bone weaker and more susceptible to fracture. Research has shown, for example, that a class of drugs
called aromastase inhibitors, may cause bone loss in some postmenopausal women. Aromastase inhibitors
Arimidex (generic name, anastrozole), Femara (generic name, letrozole) or Megace (generic name, megestrol) are
used to treat breast cancer. On the other hand, other treatments, such as the drugs tamoxifen or Evista (generic
name, raloxifene) can protect cancer patients against bone loss. In addition to treating and preventing breast
cancer in high risk women, Evista, for example, is used to treat osteoporosis.
Monitoring bone health during and after cancer treatment is important. Many physicians monitor cancer
patients with DEXA (Dual Energy X-ray Absorptiometry) scans, taking a scan at the beginning of treatment
to use as a baseline bone density measurement. DEXA is the most widely available method of bone
densitometry. During a DEXA exam, the patient lies fully clothed on a padded table while the system
scans one or more areas of bone (usually the lower spine or hip). Click here to learn more about
measuring bone density.
Maintaining bone health during and after cancer treatment involves maintaining a diet rich in calcium and
vitamin D, performing weight baring exercise when possible, trying to get sunlight (for vitamin D absorption), and
avoiding smoking and alcohol consumption. Cancer patients and survivors experiencing bone pain should see their
physicians immediately. Patients who develop osteoporosis should receive appropriate treatment. A class of drugs
called bisphosphonates is often used to treat osteoporosis or prevent the disease in high risk women. Examples of
bisphosphonates include Fosamax (generic name, alendronate) and Actonel (generic name, risedronate sodium).
For breast cancer patients, bone is a common site to which the cancer can spread. Approximately 45% of breast
cancers spread first to the bone (called bone metastases). The bones of the spine, ribs, pelvis, skull, and
long bones of the arms and legs are most often affected. There are two types of bone metastases: osteolytic
and osteoblastic. With osteolytic metastases, the cancer eats away at the bone, forming holes. This most
often occurs in the legs, hip, or pelvis. Osteoblastic metastases actually increase bone mineral density
but also cause bones to fracture easily. Both types of bone metastases cause pain. According to recent
research by Christopher Meyer, MD and Kevin James, MD of the Houston Center for Spinal Reconstruction
and Disk Replacement, about 75% of the over 200,000 patients with advanced breast cancer will experience
bone metastases. Severe pain occurs in about three-fourths of these patients. In addition, up to 50% of
patients with metastases will experience bone fractures each year.
Treatment of bone metastases usually focuses on relieving bone pain associated with the cancer and
preventing bone fractures. Bone pain can be treated by radiation therapy. According to Drs. Meyer
and James, between 25% and 40% of breast cancer patients with bone metastases undergo radiation therapy to treat bone pain.
Research into other treatments for bone pain is promising. For example, a procedure called balloon
kyphoplasty, is a minimally invasive technique to relieve spinal pain. Initial research has shown
that balloon kyphoplasty can provide immediate pain relief. It can also restore vertebral body
height, increase the strength of the vertebral body, and restore stiffness. The procedure, which
is still in experimental stages, can be performed under local or general anesthesia and involves
using x-ray (fluoroscopy) guidance to help the surgeon place a hollow needle into the collapsed
vertebra. Once the needle is placed, a small orthopaedic balloon is then inserted through the
needle and into the vertebra. When the balloon gently inflates, it restores the soft bone to
its natural shape. The balloon is then deflated and removed. The surgeon uses a special liquid
cement (methylmethacrylate) to fill the cavity inside the bone, which helps prevent future
collapses. The procedures typically lasts about one hour.
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Ballon Kyphoplasty
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Two balloons are usually placed into the fractured bone to provide adequate support. The incision is usually about 1/3 inch.
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The balloons are then inflated to raise and restore the bone into its typical position.
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When inflation occurs, a cavity is created. After the bone moves to the proper position, the balloons are removed.
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Bone cement is inserted for cohesion.
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The cement hardens and holds the bone in place.
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Images Courtesy of Medtronic
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Kyphoplasty is a new procedure, so access to treatment is limited. According to Medtronic, a company specializing
in medical technology to treat a variety of diseases and disorders, approximately 340,000 patients and 400,000
spinal fractures worldwide have been treated with balloon kyphoplasty. Medtronic reported that 77 patients
who recently underwent balloon kyphoplasty experienced complete relief from bone pain.
Additional Resources and References
Updated: April 7, 2008
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