Bone Loss

Prevent fractures through early prevention

Strong bones are an important part of overall health and well-being and are especially important for people with cancer. Maintaining healthy bones can help avoid loss of bone mass, which is common as people age. However, the loss of bone mass can also be triggered by cancer treatment as well as the disease itself.

The loss of bone mass or bone density is known as osteoporosis. This condition occurs when the bone cells that help rebuild bone (osteoblasts) don’t get replaced at the same rate as those that naturally break down bone (osteoclasts). Bones become thin and porous (full of tiny holes).

The spine, wrist and hip are the most susceptible to fracture. Osteoporosis usually does not cause symptoms, but any of the following may be a sign of the condition:

• Weight loss
• Stooped posture
• Curving of the upper back
• Bone tenderness
• Loss of 1-2 inches in height

Osteopenia is another bone condition; with osteopenia, bones are less dense, but not as severely as with osteoporosis. Osteopenia increases the risk for osteoporosis. Osteoporosis is related to such bone complications as an increased risk of fracture (break) or pain and disability.

Cancer and bone loss

Many different types of cancer treatment may contribute to loss of bone density. Radiation therapy to the pelvic region can cause bone loss, increasing the risk of pelvic and hip fractures, especially for women older than 65. In addition, some chemotherapy drugs decrease the level of calcium in the body, which can lead to bone loss. Other medications, such as corticosteroids (prednisone) and synthetic thyroid hormone agents, have also been found to increase the risk of osteoporosis.

Hormone therapy is a major factor in bone loss because this treatment reduces the level of estrogen (women) or testosterone (men), both of which are essential for maintaining optimal bone density. Hormone therapy for estrogen receptor (ER)-positive or progesterone receptor (PR)-positive breast cancer or androgen-deprivation therapy for men with prostate cancer has been shown to increase the risk of osteoporosis. If your doctor prescribes hormone or androgen-deprivation therapy, be sure to ask about the risk of osteoporosis and ways to prevent the condition.

Bone destruction can also be caused by cancer metastasis (spread). Metastasis to bone is most common with breast, prostate and lung cancer and multiple myeloma. Bone metastasis causes weakening of bone and can cause pain. Several tests can detect bone metastasis; the standard test is a bone scan, which can detect bone metastasis before pain or other symptoms occur. Sometimes, other tests such as computerized tomography (CT) or magnetic resonance imaging (MRI) may be needed to determine if cancer has spread to the bone.

Bone mass is most often measured with a bone density scan, also known as a dual-energy X-ray absorptiometry (DEXA). Your doctor may want to have a bone density scan done before cancer treatment begins, to get a baseline measurement that can be compared with later measurements, taken during cancer treatment or after it has been completed.

In its early stage, osteoporosis usually causes no pain or other symptoms. Once bones begin to weaken, signs and symptoms of osteoporosis include loss of height, a stooped posture, and pain and/or stiffness in the back or joints. If you have any of these signs or symptoms, tell your doctor.

Management of bone complications

There are many ways to prevent or manage osteoporosis or to treat bone metastasis, and it is important to take action against bone loss before it starts. If your treatment plan calls for hormone therapy or another therapy that increases risk for bone loss, your doctor may order a bone density scan. If the test shows early signs of bone loss, your doctor may prescribe a bone-modifying agent. These work by slowing the rate of bone loss, helping to decrease new bone damage, and promoting bone healing. Bone-modifying agents are also an option when cancer has metastasized to bone.

Several bone-modifying agents are available. Their use depends on your type of cancer and whether you need to prevent osteoporosis or treat bone metastasis. Many bone-modifying agents belong to a class of drugs known as bisphosphonates.

These drugs are taken by mouth and are options for treating osteoporosis in people with or without cancer.

The use of bone-modifying agents has helped to reduce pain and bone complications, but they are linked with a rare but serious side effect called osteonecrosis of the jaw. In this condition, cells in the jawbone start to die from everyday wear and tear as well as from damage that can happen during routine dental procedures. Symptoms of this condition include pain, numbness or swelling of the jaw; loose teeth; infection of the gums; or slow healing after injury or surgery involving the gums. Experts recommend that you visit your dentist to ensure your teeth and gums are healthy before you start treatment with a bone-modifying agent. You should also tell your dentist that you are taking a bone-modifying agent so that he or she can take steps to minimize your risk for osteonecrosis of the jaw.

Other treatments are also available for bone metastasis. Your doctor may prescribe external-beam radiation therapy to relieve bone symptoms, especially if the involved bone is a weight-bearing one. Radiation beams are targeted to the area of the metastasis and relief of symptoms is usually immediate and complete. Radiation can also be injected into your veins with use of drugs known as radiopharmaceuticals to relieve pain. These drugs are used when there are many sites of painful metastases.

Surgery may also be needed to treat a bone fracture or to relieve pressure on the spinal cord caused by bone metastasis.

In addition to these treatments, your doctor may also suggest physical therapy, which can enhance your quality of life by helping to manage pain, decrease the chance of bone fractures, and increase mobility and safety. Physical therapy usually consists of stretching, balance and stability exercises.

Be sure to talk with your doctor or other member of your health care team if you have bone pain.

Help keep your bones healthy and strong

• Adhere to all treatments prescribed by your doctor.
• Get enough calcium and vitamin D. For calcium, consume plenty of dairy foods (such as milk or cheese); dark, leafy greens; and beans. For vitamin D, look for vitamin D-fortified milk and cereal and fatty fish, such as salmon, tuna, sardines and swordfish. Your doctor may also suggest calcium and vitamin D supplements to ensure that you get enough of these two essential elements.
• Spend some time in the sun to help your body make vitamin D. Just 5 to 10 minutes two or three days a week is all you need. Remember to apply sunscreen if you will be in the sun for a longer period.
• Make light exercise part of your daily routine as much as you can. Weight-bearing activities, such as walking, dancing and climbing stairs, are best because they help stimulate the production of bone-forming cells. Light weightlifting is also helpful.
• Maintain a healthy weight. If you are underweight, you are more likely to have bone loss and fractures.
• Help prevent falls by wearing shoes that fit well, avoiding clutter and small rugs in your home, and being careful when walking after taking pain medicine. Falling is the most common cause of fracture for people with osteoporosis. If you feel unsteady on your feet, it may be helpful to do exercises that improve your balance.