Bone metastases

Cancer that starts in one part of the body and spreads to the bone is called bone metastases. It's sometimes called secondary bone cancer or metastatic bone disease. Cancer that starts in the bone is called primary bone cancer. Bone metastases are much more common than primary bone cancer.

Metastatic cancer is also called:

• metastatic tumour, tumours or disease
• metastasis (one cancerous tumour)
• metastases (more than one cancerous tumour)
• advanced cancer

Some kinds of cancer are more likely to spread to the bones than others. The most common types of cancer that spread to the bones are:

• breast
• prostate
• lung
• kidney
• thyroid
• uterus

Cancer can spread to any bone in the body. The most common places for bone metastases are the vertebrae (bones of the spine), ribs, pelvis (hip bone), sternum (breastbone) and skull. Sometimes only one area of bone is affected. Other times metastases develop in several bones at the same time.

Bone is constantly being formed and broken down. This is a normal process that keeps bone healthy and strong. Metastatic cancer can upset this process. It can affect the normal balance between new and old bone and change the structure and function of the bone.

Osteoblastic metastases develop when cancer cells invade the bone and cause too many bone cells to form. The bone becomes very dense (sclerotic). Osteoblastic metastases often happen when prostate cancer spreads to the bone.

Osteolytic metastases develop when metastatic cancer cells break down too much of the bone, making it very weak. Holes may develop in the bones as the bone is destroyed. Osteolytic metastases often happen when breast cancer spreads to the bone.

Osteolytic metastases are more common than osteoblastic metastases. And both can happen together in the same area of bone, such as with metastatic breast cancer.

The symptoms of bone metastases vary depending on which bones are affected and how many bones are affected. Other health conditions can cause the same symptoms as bone metastases.

The most common symptom of bone metastases, and usually the first to happen, is pain in the bone. Bone pain can come and go, or it can be constant. It is often worse at night. The pain may be only in one area or it may spread throughout the body. It may be a dull ache or a sharp pain. There may also be swelling along with bone pain.

Other signs and symptoms of bone metastases include broken bones (fractures), most often the ribs, vertebrae and long bones of the legs.

Bone metastases can also cause the following cancer-related emergencies.

Hypercalcemia means that there is too much calcium in the blood. Symptoms include constipation, loss of appetite, nausea, the need to urinate (pee) often, extreme thirst and confusion.

Spinal cord compression is pressure on the nerves of the spinal cord, which can be caused by vertebrae damaged from bone metastases. Symptoms include loss of balance, weakness or numbness in the legs and sometimes arms, and loss of bladder or bowel control (incontinence).

Diagnosis is the process of finding out the cause of a health problem. The following tests may be used to diagnose bone metastases. Many of the same tests can also help your healthcare team plan treatment and watch for changes to the cancer.

Your health history is a record of your symptoms, risks and all the medical events and problems you have had in the past. Your doctor will ask questions about a personal history of symptoms that suggest bone metastases.

A physical exam allows your doctor to look for any signs of bone metastases. Your doctor may feel areas that are causing pain or other symptoms and look for swelling.

Find out more about a physical exam.

The types of blood tests used to help diagnose bone metastases include the following.

A complete blood count (CBC) is done to check your general health and how well the bone marrow is working.

Calcium and alkaline phosphatase levels in the blood may be measured. High levels may mean there is damage to the bone from bone metastases.

Tumour markers may be measured if you have had cancer before. These tests measure the amount of a specific protein in the body. The type of tumour marker used depends on the type of cancer you had before. For example, if you had prostate cancer in the past, your doctor may measure the levels of prostate-specific antigen (PSA) in your blood. High PSA levels may mean that prostate cancer has come back and spread to the bone.

Find out more about a complete blood count (CBC), blood chemistry tests and tumour markers.

Imaging tests are an important part of diagnosing bone metastases. It is common for people to have one or more imaging tests when the doctor thinks cancer has spread to the bone. The imaging tests used to diagnose bone metastases include the following.

An x-ray is usually one of the first tests used to check symptoms like bone pain. An x-ray can also show breaks of the bones.

A bone scan is used to check the whole skeleton for bone metastases, especially when there is bone pain in several places. A bone scan can often find bone metastases earlier than an x-ray, so it is sometimes used during follow-up after cancer treatment even when there are no symptoms of bone metastases.

A CT scan is used if x-rays and a bone scan are normal but your doctor still thinks there are bone metastases. It is also used to measure the size of a bone tumour. Doctors may also use a CT scan to guide them to a tumour during a needle biopsy to get tissue samples.

An MRI is used to check for spinal cord compression. It may be used if the results of a CT scan are not clear. An MRI can also be used to check if metastatic cancer has spread to the bone marrow.

A PET scan looks at the whole skeleton and may be used to check if there are very small bone metastases. It's sometimes used along with a CT scan.

Find out more about these imaging tests and procedures.

A biopsy is a test that removes cells or tissues to examine them under a microscope. It is sometimes needed to diagnose bone metastases. But if you have a history of cancer, doctors usually base a diagnosis of bone metastases on the results of imaging tests.

Sometimes a biopsy is done if the primary cancer (where the cancer started) is not known. A needle or surgical biopsy is usually used.

Find out more about biopsies.

If bone metastases are found before the primary cancer is diagnosed, the doctor may order tests to find out where the cancer started. These tests may include:

• mammography to check for breast cancer
• x-ray or CT scan of the chest to check for lung cancer
• transrectal ultrasound (TRUS) to check for prostate cancer
• tumour markers to try to identify where the cancer started

If you have bone metastases, your healthcare team will create a treatment plan just for you. It will be based on your needs and usually includes a combination of different treatments. Treatments can control and slow the growth of bone metastases, but the metastases usually don't go away completely. You will also be offered supportive therapies to manage or prevent problems caused by bone metastases.

When deciding which treatments and supportive therapies to offer for bone metastases, your healthcare team will consider:

• where the cancer started
• your symptoms
• how many bones are affected by cancer
• cancer treatments you've already had
• what you prefer or want

You may be offered the following treatments and supportive therapies for bone metastases.

Radiation therapy is a common treatment for bone metastases. It may be given as external radiation therapy or systemic radiation therapy.

External radiation therapy may be used to treat bone pain and spinal cord compression. It is also used to prevent or help heal broken bones. During external radiation therapy, a machine directs a beam of radiation through the skin. It is directed at a specific area of bone where there is pain or that needs treatment. How long external radiation is used depends on things like the goal of treatment and the number of bones affected by cancer. A short course of radiation therapy is often used for bone metastases. Usually it is given once a day for 5 days. Or just one radiation treatment may be given.

Systemic radiation therapy may be used when there is pain in many bones. It is most often used for osteoblastic metastases from prostate cancer. Systemic radiation therapy uses drugs with radioactive materials. These drugs are usually given intravenously (through a needle into a vein). They travel through the blood to cancer cells in the bone. Usually only one dose of systemic radiation is given. The most common radioactive materials used for systemic radiation therapy are:

• radium-223 (Xofigo)
• samarium-153 (Quadramet)

Side effects of radiation therapy will depend mainly on the type of radiation therapy, the area of the body treated and the length of treatment. The most common side effect of radiation therapy to the bone is a temporary increase in pain before it gets better or goes away completely.

Find out more about radiation therapy.

Bisphosphonates are drugs that help slow the breakdown of bone. They are standard therapy for bone metastases. They are used to help manage and prevent problems such as hypercalcemia, bone pain and broken bones.

Bisphosphonates are given depending on things like where the cancer started, the number of bones affected by cancer, the chance of developing bone problems (such as breaks) and life expectancy. These drugs are usually used along with other therapies such as radiation therapy, chemotherapy and pain medicines.

The most common bisphosphonates used for bone metastases include:

• clodronate (Clasteon)
• pamidronate
• zoledronic acid (Zometa)

Bisphosphonates are most often given through a needle into a vein. These drugs are usually given once every month or once every 3 months, but they may be given more often. Bisphosphonates may also be given once a day as a pill by mouth (orally).

Side effects of bisphosphonates will depend mainly on the type of drug, the dose and the length of treatment. Common side effects of bisphosphonates are flu-like symptoms, diarrhea, nausea and heartburn.

Find out more about bisphosphonates.

Denosumab is a monoclonal antibody that finds and attaches to RANKL, which is a substance on the surface of bone cells. RANKL helps break down bones. When RANKL is blocked, bones do not break down as quickly.

Denosumab may be used instead of bisphosphonates to slow down or stop bone loss caused by bone metastases from prostate cancer, breast cancer, non–small cell lung cancer and other solid tumours. It may also be used to treat hypercalcemia.

Denosumab is given by a needle inserted just under the skin (called subcutaneous injection). It is usually given every 4 weeks or every 12 weeks. While taking denosumab, you may be told to take calcium and vitamin D pills. Because denosumab can cause problems with your jaw, your healthcare team may recommend that you visit your dentist before starting this medicine. It's important that you take care of your mouth and teeth while on denosumab.

The most common side effect of denosumab is low levels of calcium in the blood. Other less common side effects include poor appetite, constipation or diarrhea, fatigue, muscle or joint pain, nausea and vomiting. Tell your healthcare team if you have these side effects or others you think might be from denosumab.

Pain medicines are commonly used to manage pain caused by bone metastases. They are often given because other treatments may take a while to relieve pain or may not stop pain completely.

The most common pain medicines used for bone metastases are taken as a pill by mouth, including: ·

• acetaminophen (Tylenol)
• nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin, Advil, Nuprin) and naproxen (Aleve, Naprosyn)
• opioids such as morphine, hydromorphone (Dilaudid) and codeine
• medicines for nerve pain, such as gabapentin (Neurontin) and pregabalin (Lyrica)

Side effects of pain medicines will depend mainly on the type of drug, the dose and the length of treatment. Common side effects of pain medicines are upset stomach, drowsiness and constipation.

Find out more about pain and how to manage it.

Chemotherapy may help shrink bone metastases and relieve symptoms such as pain. It may be an option if there are several areas of bone metastases and the cancer is likely to respond to chemotherapy.

Chemotherapy is used to treat many types of metastatic cancer. The type of chemotherapy drug or combination of drugs used depends on where the cancer started.

Chemotherapy drugs circulate (flow) throughout the body and destroy cancer cells. The drugs, the dose and the schedule will vary for each person. Chemotherapy is sometimes used along with other treatments such as radiation therapy and bisphosphonates.

Side effects will depend mainly on the type of drug, the dose and how it's given. Common side effects of many chemotherapy drugs are low blood cell counts (called bone marrow suppression), nausea and vomiting, mouth problems and bowel problems.

Find out more about chemotherapy.

Hormonal therapy adds, blocks or removes certain hormones to slow or stop the growth of some types of cancer cells that need hormones to grow. Drugs, surgery or radiation therapy can be used as hormonal therapy to change hormone levels or block their effects.

Hormonal therapy may be offered for some types of cancer that have spread to the bone, such as breast and prostate cancers. It is often used to relieve symptoms like bone pain. It often has fewer side effects than chemotherapy.

Side effects of hormone therapy will depend mainly on the type of hormonal therapy. Common side effects include hot flashes and less interest in sex.

Find out more about hormonal therapy.

Targeted therapy uses drugs that find and attach to specific substances (such as proteins) on the surface of cancer cells or inside cancer cells. These substances help send signals that tell cells to grow or divide. The targeted therapy drugs block the substances to stop or slow the growth and spread of cancer cells.

Targeted therapy may be used to control the growth of bone metastases from some types of cancer. The type of drug used will depend on where the cancer started. Targeted therapy is given through a needle into a vein or as a pill by mouth. It is most often used along with chemotherapy.

Side effects of targeted therapy depend mainly on the type and dose of the drug. Common side effects include flu-like symptoms and fatigue. Most side effects go away on their own or can be treated. Tell your healthcare team if you have these side effects or others you think might be from targeted therapy.

Find out more about targeted therapy.

Immunotherapy boosts the immune system or helps the immune system to find cancer and attack it. Immunotherapy may be given as a treatment on its own, but it is most often used with other types of therapy such as chemotherapy and radiation therapy.

The type of immunotherapy drug used will depend on where the cancer started.

Side effects of immunotherapy depend mainly on the type and dose of the drug. Common side effects include flu-like symptoms and fatigue. Most side effects go away on their own or can be treated. Tell your healthcare team if you have these side effects or others you think might be from immunotherapy.

Find out more about immunotherapy.

Surgery may be used to repair a broken bone caused by metastases. It may also be used to make bone more stable and prevent it from breaking. Metal screws, pins, rods and plates can be placed during surgery to strengthen and support the bone. Surgery may be used to relieve pain from a broken bone. It can also help prevent or treat spinal cord compression. Most people with bone metastases need to be in good overall health to have surgery.

Side effects of surgery will depend mainly on the place of the surgery and your overall health. Common side effects of surgery are pain, bleeding and wound infection.

Find out more about surgery.

Bone cement makes bone strong and stable. It may be used to relieve pain from a break. It may also be used to prevent a bone from breaking and improve mobility (how easily you can move around). Bone cement is most often used to treat bones of the spine, pelvis, arms and legs.

Bone cement is a substance called polymethyl methacrylate. It is injected into a bone through the skin. This procedure is also called percutaneous osteoplasty. When it is done on bones of the spine, it is called vertebroplasty. The doctor gives a local anesthetic to freeze the area before the needle is inserted. The doctor uses fluoroscopy imaging or a CT scan to guide the needle containing the bone cement to the right area of bone.

Possible side effects of injecting bone cement are pain and infection.

Clinical trials look at new ways to prevent, find or treat cancer. Talk to your doctor about clinical trials open to people with metastatic cancer in Canada. Find out more about clinical trials.

You may want to consider a type of care to make you feel better without treating the cancer itself. This may be because the cancer treatments don't work anymore, they're not likely to improve your condition or they may cause side effects that are hard to cope with. There may also be other reasons why you can't have or don't want cancer treatment.

Talk to your healthcare team. They can help you choose care and treatment for advanced cancer.

Adjusting to life with bone metastases often takes time. In many cases, it is a chronic condition. A person with bone metastases may have concerns about the following.

People often get pain with bone metastases. Many treatments and supportive therapies are given to help relieve pain. Tell your healthcare team if your treatments are not relieving the pain. You may be referred to doctors and nurses that specialize in ways to manage pain. Having good pain control will help you feel better so you can continue with activities you enjoy.

Bone metastases may lessen your ability to move around. Bones are often weak and can break easily. You can do the following to lower the risk of falling and keep your environment safe.

Try to move around and change positions slowly. Be careful when you are walking. Wear shoes or slippers with good grips on the bottom. Use a cane or walker to help keep your balance. Ask for help with walking.

Try to keep hallways and walkways clear of clutter. Use safety equipment when bathing, such as shower chairs and handrails.

Ask your healthcare team about physiotherapy and occupational therapy programs that can help with mobility problems and keep you safely active.

A diagnosis of advanced cancer can lead to questions about survival. There is no way of knowing exactly how long someone will live with bone metastases. It depends on many factors, including the type of cancer. For example, survival with bone metastases from prostate or breast cancer is often measured in years. Survival with lung cancer that has spread to the bones is often measured in months. Some people live much longer than expected, while others may die sooner than expected.

The best person to talk to about survival is your doctor. Your doctor may be able to estimate survival based on what they know about you and the type of cancer, but everyone responds differently to cancer and cancer treatments.