New medications are improving bone health for people with cancer.
Cancer can affect the bones in several different ways. Some cancers, such as multiple myeloma, start in bones. Other cancers, such as breast, prostate, lung and kidney cancer, can metastasize, or spread, to the bones. Cancer that starts in or spreads to the bones can lead to bone pain and can increase your risk for complications, including weakening of the bone, fractures (breaks) and high calcium levels in the blood, which can further damage bones.
Some cancer treatments may also affect your bones. For example, certain treatments used for breast and prostate cancer may lead to a thinning of the bones known as osteoporosis, which also increases your risk of fractures. In this e-booklet, we’ll talk about how bone pain and complications are diagnosed and treated, medications that doctors can use to help improve bone health and practical tips for taking care of your bones.
Diagnosing and Treating Bone Problems
Usually, the first step in treating bone complications is to get any bone pain under control. Pain relievers (analgesics) are very effective. These drugs include both over-the-counter and prescription medications. Over-the-counter medications include acetaminophen (Tylenol, for example), aspirin, and nonsteroidal anti-inflammatory drugs (NSAIDs) such naproxen (Aleve, for example). Prescription medications include opioids such as oxycodone, hydromorphone and morphine. The right pain medication, dose and schedule will relieve your pain without causing further problems.
Along with controlling your pain, your doctor will do tests to find out the causes of the pain and whether there is a fracture or a risk for fracture in the bone. These tests may include a bone scan or a PET scan to find out how much the cancer may be affecting the bone. Your doctor may also order an x-ray exam of your “weight-bearing” bones, such as the leg bones. If these tests reveal that you are at risk for a fracture, it’s best to treat it before there is an actual break.
Your doctor may also check to see if you have high levels of calcium in your blood, a condition called hypercalcemia. This situation can happen when cancer injures the bones, causing calcium to be released from the bone into the blood. Symptoms of high calcium levels may include nausea and vomiting, sleepiness, feeling very thirsty and urinating frequently.
Treatment of high blood calcium levels includes increasing your intake of fluids by drinking more water or having fluids given to you intravenously (through a vein) to treat or prevent dehydration. Drugs that reduce calcium levels directly may also be used.
It’s important that you tell your doctor immediately if you have severe back pain or pain in the back that develops or changes rapidly. This may mean that a bone metastasis in the spine is pressing against the spinal cord. If that is the case, urgent medical care is required. This type of pain can develop over hours to days and is often felt in the middle of the back. It may be accompanied by a feeling of weakness. Treatment for this condition may include steroid drugs, radiation and surgery.
Medications for Bone Health
In addition to the specific treatments discussed in the previous section, your doctor may also prescribe special medications to improve the health of your bones. These medications reduce the risk of fractures and the need for radiation or surgery to treat them:
•RANK ligand inhibitors
•Selective estrogen receptor modulators (SERMs)
RANK ligand inhibitors This new class of drugs works differently from other types of drugs used for bone complications. They are designed to block a factor in bone development known as RANK ligand. RANK ligand stimulates cells that break bone down. By blocking RANK ligand, RANK ligand inhibitors may increase bone density and strength.
Denosumab (Prolia) is a RANK ligand inhibitor that has been available for some time for the treatment of osteoporosis in postmenopausal women at high risk for fractures. The U.S. Food and Drug Administration has approved denosumab (under the brand name Xgeva) to help prevent skeletal-related events (SREs) in patients with solid tumors that have spread to and damaged the bone. (Denosumab is not approved to prevent bone complications in patients with multiple myeloma.) SREs include bone fractures from cancer, bone pain requiring radiation, broken bone that requires surgical repair and pressure on the spinal cord. Denosumab may also help prevent bone tumor growth in cancers such as breast or prostate cancer, which can spread to the bone.
Bisphosphonates bind to the bone surface and slow the breakdown of bone by osteoclasts. Bisphosphonates include alendronate (Fosamax, for example), ibandronate (Boniva), pamidronate (Aredia, for example), risedronate (Actonel, for example), and zoledronic acid (Zometa). These drugs kill osteoclasts or the bone destroying cells and help build bone, and the result is usually an increase in bone density.
Bisphosphonates have been shown to reduce bone loss in postmenopausal women with breast cancer receiving hormone therapy and in premenopausal women with chemotherapy-induced menopause. Similarly, bisphosphonates reduce bone loss in men with prostate cancer receiving hormone therapy. The bisphosphonate zoledronic acid is also used to treat bone pain and bone complications in people with other types of cancers that have spread to the bone.
SERMs Another class of drugs used to prevent and treat bone complications is selective estrogen receptor modulators (SERMs). The exact way SERMs act to increase bone density is not fully known, but they are believed to slow the breakdown and removal of old bone. Examples of SERMs used for people with cancer are raloxifene (Evista), tamoxifen (Nolvadex, for example), and toremifene (Fareston).
Because cancer can affect the bones in various ways, caring for your bones is a very important part of your overall care. There are tests your doctor can use to monitor your bone health as you go through treatment. There are also ways for you to strengthen your bones through good nutrition and physical exercise.
Tests for Bone Health
Doctors use a variety of tools to monitor your bone health as you go through treatment. The following tests can tell you and your doctor what your bone density is, how much risk you might have for bone fractures and whether the condition of your bones is changing because of cancer or because of medications you are taking:
• DEXA scan This test measures the density (mass) of the bones. It shows whether your bone density is normal or whether you have mild bone loss (osteopenia) or greater bone loss (osteoporosis, with reduced bone density or bone mass and weakening of the bone). Using this information, your doctor can develop a strategy to maintain your bone density or increase it.
• FRAX index Your doctor may use this test, along with bone density measurements, to assess your risk of fracture. This index can be used to predict the risk of fracture using the results of the DEXA scan as well as information based on ethnicity, age, gender, weight, and family or personal history of fractures. Other things figure in as well: whether you smoke, drink alcohol, take steroid drugs, or have osteoporosis due to some other condition or disease, such as a lack of enough calcium in the diet or rheumatoid arthritis.
• Other tests Your doctor may perform tests that measure the levels of vitamin D and calcium in your blood. Both of these minerals are needed to maintain bone health. Your doctor may also test for substances called biomarkers that show whether and how much bone is being formed or broken down. These biomarkers are measured in the blood and urine.
The Role of Nutrition
There are also ways for you to strengthen your bones through good nutrition and physical exercise. One thing you can do to maintain or improve your bone health is to make sure that you have adequate nutrition, including enough calories, calcium and vitamin D. If the body does not get enough calories through food, it will “steal” them from itself, including taking them from bone. Similarly, if the body does not get enough calcium for all of its needs through food or calcium supplements, it will take calcium from the bones, weakening them.
You need about 1,000 to 1,200 mg (milligrams) of calcium a day to help keep your bones healthy. One cup of milk provides about 250 mg of calcium. This means you need to drink about four glasses of milk every day to have an adequate intake of calcium. Calcium is also present in other food sources, but to reach the amount that is needed, many people have to take calcium supplements.
Calcium supplements are available in two forms: calcium carbonate and calcium citrate. Calcium carbonate is not well absorbed unless the stomach is acidic. If you need to take an antacid, for example, this type of calcium will not be absorbed. Calcium citrate is the preferred form of calcium to take, since it is easily absorbed (and also prevents the formation of kidney stones).
To absorb calcium, the body also needs vitamin D. We make vitamin D when the skin is exposed to sunlight, but most of us do not get enough sunlight to maintain adequate levels of vitamin D. Although it is available from a few natural sources, such as cod liver oil and fatty fish, many people have to take a vitamin D supplement to reach their daily requirement. The official recommendations for vitamin D are to take 400 to 600 IU (international units) per day, but many doctors believe this amount is too low to make sure that people have adequate vitamin D levels in their body. So it’s best to take around 1,000 to 2,000 IU of vitamin D per day.
In rare cases, taking a vitamin D supplement may cause the level of calcium in the blood to go too high. Your doctor will measure your blood calcium level to make sure this is not happening when you are taking both calcium and vitamin D supplements.
Frequently Asked Questions
Q. I’m not sure how much vitamin D is safe for me to take. How much should I be taking?
A. Most doctors will recommend that you take 1,000 to 2,000 IU of vitamin D every day. This is in addition to the vitamin D you may be getting in your multivitamin and in your calcium tablets, since many calcium tablets already have vitamin D in them. Your doctor should monitor your calcium and vitamin D levels closely and will work with your oncologist to make sure that the vitamin D is not raising the calcium levels in your blood too high. It takes a team effort to make sure that you maintain the health of your bones.
Q. What is the best way to take care of my teeth during cancer treatment?
A. The goal of starting dental care before cancer treatment is to treat infections or conditions that might cause problems during or after treatment. All dental disease should be eliminated before cancer treatment is started, but because this is not always possible, special care is needed in some situations. If you plan to have head and neck radiation, a thorough examination and full treatment of any existing dental disease are needed first. This type of radiation treatment increases the risk for a severe bone condition, known as osteoradionecrosis, caused by reduced blood flow to the jaw. Similarly, a thorough examination and treatment of dental disease are needed when antiresorptive drugs like bisphosphonates and denosumab are given, since this treatment can sometimes cause osteonecrosis of the jaw.
After cancer treatment, it’s important to maintain good dental care. See your dentist every three to six months, depending on how much dental or periodontal disease you have.
Q. I am postmenopausal and have osteopenia (mild thinning of the bone). Can bisphosphonates reduce my risk of the cancer coming back?
A. There are ongoing clinical trials that are researching whether bisphosphonates reduce the risk of recurrence of cancer, not only in bone but in other locations as well. Talk to your doctor and your oncologist to keep up-to-date on the latest research. You can also visit a number of websites for the most current information, including the patient websites of the American Society of Clinical Oncology and the National Cancer Institute.
Q. I have lung cancer and am taking prednisone. I’ve heard that this can lead to bone loss. Should I stop taking it?
A. Prednisone is a steroid often prescribed for people with lung cancer. It helps patients cope with shortness of breath, decreased energy, and loss of appetite. But prednisone does have side effects, including bone loss. Lung cancer patients take other medications, such as blood thinners, that can also affect bone health. If you are on these medications, talk with your doctor about taking one of the bisphosphonates or denosumab to help prevent bone problems. Often, you can use these drugs in combination with your cancer treatment to protect against excess bone loss. Extra vitamin D may also help you absorb more calcium to improve bone strength.
Certainly you should continue to take prednisone and any other drugs your doctor prescribes. Bone loss can be dealt with at the same time with other medications.
Q. I have severe bone pain, but I am scared to take medication for it. Can’t patients become addicted to painkillers?
A. Pain management can be an important part of cancer treatment. The most effective way to control pain is to prevent it from occurring or becoming more severe. Although fear of addiction is common, people who take medication to control pain associated with cancer or its treatments rarely become addicted. Untreated pain can have negative effects on your health and emotional well-being. Pain causes stress, depression, anxiety and fatigue. Discuss your concerns with the members of your health care team. They can offer many options for coping with cancer and bone pain.