Approved by the Cancer.Net Editorial Board, 10/2018

Osteoporosis is the most common type of bone disease. It develops when the body breaks down more bone tissue than it can replace. As a result, bones become weak and fragile. This makes them more likely to fracture or break.

Causes of bone loss

As we age, our bodies are less able to replace the cells needed to repair and rebuild bone tissue. This means that the bones may become thin and develop holes. Other factors that contribute to loss of bone mass include:

  • Bone cancer, which is cancer that starts in the bones.

  • Cancer that has spread to the bone. Cancers that most commonly spread to the bones include:

    • Breast cancer

    • Prostate cancer

    • Multiple myeloma

    • Lung cancer

  • Certain types of chemotherapy.

  • Being a woman, since women have a higher risk of osteoporosis than men. The risk of osteoporosis is especially high after menopause because of lower levels of estrogen. Estrogen is a hormone that helps maintain bone density. Some cancer treatments can cause menopause, often at an earlier age than expected.

  • Hormone therapy for breast or prostate cancer. These treatments reduce levels of estrogen or testosterone. A decrease of these hormones contributes to loss of bone mass and density.

  • Heavy smoking and excessive alcohol consumption.

  • A family history of osteoporosis.

  • Other medicines, including:

    • Steroid therapy (such as prednisone)

    • Synthetic thyroid hormone therapy

    • Drugs for heartburn

  • Long-term bed rest and inactivity.

  • Poor nutrition and not getting enough calcium and vitamin D.

  • Race and ethnic background. People who are white or Asian have an increased risk of developing osteoporosis.

Fractures from bone loss

Fractures or bone breaks cause pain and movement problems. These problems can interfere with a person’s daily life. People with bone cancer or cancer that has spread to the bones are more likely to experience fractures. Talk with your health care team about whether you have a high risk of fractures and how to lower your risk.

Signs and symptoms of bone loss

Loss of bone mass does not happen suddenly. Often, people do not notice it until they have pain, loss of function, or a fracture. Some people mistake the signs of serious bone problems for arthritis-like symptoms.

Talk with your health care team about any symptoms you may experience, including:

  • Back pain, often caused by a compression fracture or collapsed vertebra

  • Loss of height over time

  • Stooped posture or curved upper back

  • Painful joints or stiffness

  • Breaking a bone more easily than expected, such as after a minor injury

Relieving side effects is an important part of cancer care and treatment. This is called palliative care or supportive care.

Diagnosing bone loss

The most common test used to measure bone mass is a bone density scan. This is also called a dual energy X-ray absorptiometry (DEXA) scan. You may have this test before, during, and after cancer treatment.

A bone density scan measures the strength of the bone by looking at the amount of calcium it contains. Usually your doctor will take the measurements in your hip or the lower spine. Depending on how low your bone mineral density is, your doctor may diagnose osteopenia or osteoporosis. Osteopenia is mild bone loss.

Treating and managing bone loss

Treatment for bone loss often involves the use of bone-modifying drugs. These drugs slow the rate of bone thinning. They may also reduce new bone damage and promote healing. People who have bone pain from metastatic cancer also often receive these drugs. Bone-modifying drugs include:

  • Bisphosphonates, which block the cells that destroy bone, called osteoclasts

  • RANK ligand inhibitors, such as denosumab (Prolia, Xgeva)

Osteonecrosis of the jaw is a condition possibly linked with bone-modifying drugs. It is an uncommon but serious condition. The symptoms include pain, swelling, and infection of the jaw; loose teeth; and exposed bone.

Your doctor may recommend seeing a dentist before bone-strengthening treatment begins. But before having any dental procedures, tell your dentist you are receiving treatment with a bone-modifying drug.

Managing bone loss and its symptoms may also include the following.

Taking calcium and vitamin D supplements. The current recommendations are listed below. Talk with your health care team before starting any vitamin or mineral supplement.

  • Vitamin D: 800 international units (IU) per day for women of all ages

  • Calcium supplements for women before menopause: 1,000 milligrams (mg) per day

  • Calcium supplements for women after menopause: 1,200 mg per day

Exercising. Weight-bearing physical activity such as walking, dancing, stair climbing, and tai chi puts stress on your bones. This stress triggers the body to make cells that form bone. Regular weight-bearing exercise also builds strong muscles, which can help your balance. Your doctor can recommend an exercise plan based on your needs, physical abilities, and fitness level.

Maintaining a healthy weight. Eating a well-balanced diet is important to bone health. Being underweight can contribute to bone loss and fractures.

Preventing falls. Falling is the main cause of fractures for people with osteoporosis. Many factors can increase your risk of falling:

  • Poor vision

  • Shoes that do not fit well

  • A cluttered living space

  • Mental impairment

  • Drowsiness related to pain medicine

  • Poor concentration

To help prevent falls, try exercises to improve your balance. Before starting any exercises, talk with your health care team. They can direct you to helpful resources.

Related Resources

Types of Cancer

What is Metastasis?

ASCO Answers Fact Sheet: When Cancer Spreads to the Bone

More Information

Lab Tests Online: Osteoporosis

LIVESTRONG Foundation: Osteoporosis

National Osteoporosis Foundation: Osteoporosis