What is bone cancer?
Normal bone tissue
Bone is the supporting framework of your body. Most bones are hollow. The outer part of bones is a network of fibrous tissue called matrix onto which calcium salts are laid down.
The hard outer layer of bones is made of compact (cortical) bone, which covers the lighter spongy (trabecular) bone inside. The outside of the bone is covered with a layer of fibrous tissue called periosteum. Some bones are hollow and have a space called the medullary cavity which contains the soft tissue called bone marrow (discussed below). The tissue lining the medullary cavity is called endosteum. At each end of the bone is a zone of a softer form of bone-like tissue called cartilage.
Cartilage is softer than bone but more firm than most tissues. It is made of a fibrous tissue matrix mixed with a gel-like substance that does not contain much calcium.
Most bones start out as cartilage. The body then lays calcium down onto the cartilage to form bone. After the bone is formed, some cartilage may remain at the ends to act as a cushion between bones. This cartilage, along with ligaments and some other tissues connect bones to form a joint. In adults, cartilage is mainly found at the end of some bones as part of a joint. It is also seen at the place in the chest where the ribs meet the sternum (breastbone) and in parts of the face. The trachea (windpipe), larynx (voice box), and the outer part of the ear are other structures that contain cartilage.
Bone itself is very hard and strong. Some bone is able to support as much as 12,000 pounds per square inch. It takes as much as 1,200 to 1,800 pounds of pressure to break the femur (thigh bone). The bone itself contains 2 kinds of cells. The osteoblast is the cell that lays down new bone, and the osteoclast is the cell that dissolves old bone. Bone often looks as if it doesn’t change much, but the truth is that it is very active. Throughout our bodies, new bone is always forming while old bone is dissolving.
In some bones the marrow is only fatty tissue. The marrow in other bones is a mixture of fat cells and blood-forming cells. The blood-forming cells produce red blood cells, white blood cells, and blood platelets. Other cells in the marrow include plasma cells, fibroblasts, and reticuloendothelial cells.
Cells from any of these tissues can develop into a cancer.
Types of bone tumors
Most of the time when someone with cancer is told they have cancer in the bones, the doctor is talking about a cancer that has spread to the bones from somewhere else. This is called metastatic cancer. It can be seen in many different types of advanced cancer, like breast cancer, prostate cancer, and lung cancer. When these cancers in the bone are looked at under a microscope, they look like the tissue they came from. For example, if someone has lung cancer that has spread to bone, the cells of the cancer in the bone still look and act like lung cancer cells. They do not look or act like bone cancer cells, even though they are in the bones. Since these cancer cells still act like lung cancer cells, they still need to be treated with drugs that are used for lung cancer.
Other kinds of cancers that are sometimes called “bone cancers” start in the blood forming cells of the bone marrow − not in the bone itself. The most common cancer that starts in the bone marrow and causes bone tumors is called multiple myeloma. Another cancer that starts in the bone marrow is leukemia, but it is generally considered a blood cancer rather than a bone cancer. Sometimes lymphomas, which more often start in lymph nodes, can start in bone marrow. Multiple myeloma, lymphoma, and leukemia are not discussed in this document. For more information on these cancers, refer to the individual document for each.
A primary bone tumor starts in the bone itself. True (or primary) bone cancers are called sarcomas. Sarcomas are cancers that start in bone, muscle, fibrous tissue, blood vessels, fat tissue, as well as some other tissues. They can develop anywhere in the body.
There are several different types of bone tumors. Their names are based on the area of bone or surrounding tissue that is affected and the kind of cells forming the tumor. Some primary bone tumors are benign (not cancerous), and others are malignant (cancerous). Most bone cancers are sarcomas.
Benign bone tumors
Benign tumors do not spread to other tissues and organs and are not usually life threatening. They are generally cured by surgery. Types of benign bone tumors include:
- Osteoid osteoma (OS-tee-oyd OS-tee-oh-ma)
- Osteoblastoma (OS-tee-oh-blas-TOE-muh)
- Osteochondroma (OS-tee-oh-kon-DROH-muh)
- Enchondroma (en-kon-DROH-muh)
- Chondromyxoid (kon-dro-MIX-oyd) fibroma.
These benign tumors are not discussed further in this document, which is limited to bone cancers.
Malignant bone tumors
Osteosarcoma: Osteosarcoma (also called osteogenic sarcoma) is the most common primary bone cancer. This cancer starts in the bone cells. It most often occurs in young people between the ages of 10 and 30, but about 10% of osteosarcoma cases develop in people in their 60s and 70s. It is rare in middle-aged people, and is more common in males than females. These tumors develop most often in bones of the arms, legs, or pelvis.
Chondrosarcoma: Chondrosarcoma (KON-droh-sar-KOH-muh) is a cancer of cartilage cells. It is the second most common primary bone cancer. This cancer is rare in people younger than 20. After age 20, the risk of getting a chondrosarcoma goes up until about age 75. Women get this cancer as often as men.
Chondrosarcomas can develop anywhere there is cartilage. Most develop in bones such as the pelvis, leg bone or arm bone. Occasionally, chondrosarcoma will develop in the trachea, larynx, and chest wall. Other sites are the scapula (shoulder blade), ribs, or skull.
Benign (non-cancerous) tumors of cartilage are more common than malignant ones. These are called enchondromas. Another type of benign tumor that has cartilage is a bony projection capped by cartilage called an osteochondroma. These benign tumors rarely turn into cancer. There is a slightly higher chance of cancer developing in people who have many of these tumors, but this is still not common.
Chondrosarcomas are classified by grade, which measures how fast they grow. The grade is assigned by the pathologist (a doctor specially trained to examine and diagnose tissue samples under a microscope). The lower the grade, the slower the cancer grows. When a cancer is slow growing, the chance that it will spread is lower and so the outlook is better. Most chondrosarcomas are either low grade (grade I) or intermediate grade (grade II). High-grade (grade III) chondrosarcomas, which are the most likely to spread, are less common.
Some chondrosarcomas have distinctive features under a microscope. These variants of chondrosarcoma can have a different prognosis (outlook) than usual chondrosarcomas.
- Dedifferentiated(DEE- dih-feh-REN-shee-AY-ted) chondrosarcomas start out as typical chondrosarcomas but then some parts of the tumor change into cells like those of a high-grade sarcoma (such as high grade forms of malignant fibrous histiocytoma [HIS-tee-oh-sy-TOH-muh], osteosarcoma, or fibrosarcoma). This variant of chondrosarcoma tends to occur in older patients and is more aggressive than usual chondrosarcomas.
- Clear cell chondrosarcomasare rare and grow slowly. They rarely spread to other parts of the body unless they have already come back several times in the original location.
- Mesenchymal(meh-ZEN-kih-mul) chondrosarcomas can grow rapidly, but like Ewing tumor, are sensitive to treatment with radiation and chemotherapy.
Ewing tumor: Ewing tumor is the third most common primary bone cancer, and the second most common in children, adolescents, and young adults. This cancer (also called Ewing sarcoma) is named after the doctor who first described it in 1921, Dr. James Ewing. Most Ewing tumors develop in bones, but they can start in other tissues and organs. The most common sites for this cancer are the pelvis, the chest wall (such as the ribs or shoulder blades), and the long bones of the legs or arms. This cancer is most common in children and teenagers and is rare in adults older than 30. Ewing tumors occur most often in white people and are very rare among African Americans and Asian Americans.
Malignant fibrous histiocytoma: Malignant fibrous histiocytoma (MFH) more often starts in soft tissue (connective tissues such as ligaments, tendons, fat, and muscle) than in bones. This cancer is also known as pleomorphic undifferentiated sarcoma, especially when it starts in soft tissues. When MFH occurs in bones, it usually affects the legs (often around the knees) or arms. This cancer most often occurs in elderly and middle-aged adults and is rare among children. MFH mostly tends to grow locally, but it can spread to distant sites, like the lungs.
Fibrosarcoma: This is another type of cancer that develops more often in soft tissues than it does in bones. Fibrosarcoma usually occurs in elderly and middle-aged adults. Bones in the legs, arms, and jaw are most often affected.
Giant cell tumor of bone: This type of primary bone tumor has benign and malignant forms. The benign (non-cancerous) form is most common. Giant cell bone tumors typically affect the leg (usually near the knees) or arm bones of young and middle-aged adults. They don’t often spread to distant sites, but tend to come back where they started after surgery (this is called local recurrence). This can happen several times. With each recurrence, the tumor becomes more likely to spread to other parts of the body. Rarely, a malignant giant cell bone tumor spreads to other parts of the body without first recurring locally.
Chordoma: This primary tumor of bone usually occurs in the base of the skull and bones of the spine. It develops most often in adults older than 30, and is about twice as common in men as in women. Chordomas tend to grow slowly and often do not spread to other parts of the body, but they often come back in the same area if they are not removed completely. The lymph nodes, the lungs, and the liver are the most common areas for secondary tumor spread.
Which cancers spread to the bones?
Any cancer can spread to the bone. The most common cancers to do so are
- Prostate cancer
- Breast cancer
- Lung cancer
- Kidney cancer
- Thyroid cancer
Other cancers that develop in bones
Non-Hodgkin lymphoma generally develops in lymph nodes but sometimes starts in the bone. Primary non-Hodgkin lymphoma of the bone is often a widespread disease because multiple sites in the body are usually involved. The outlook is similar to other non-Hodgkin lymphomas of the same subtype and stage. Primary lymphoma of the bone is given the same treatment as lymphomas that start in lymph nodes − it is not treated like a primary bone sarcoma.
Multiple myeloma almost always develops in bones, but doctors do not consider it a primary bone cancer because it develops from the plasma cells of the bone marrow (the soft inner part of some bones). Although it causes bone destruction, it is no more a bone cancer than is leukemia. It is treated as a widespread disease. At times, myeloma can be first found as a single tumor (called a plasmacytoma) in a single bone, but most of the time it will spread to the marrow of other bones.
Where a cancer starts is called the primary cancer. If some cells break away from the primary cancer and move to another part of the body they can form another tumor – a secondary cancer. Cancer that has spread into the bone from another part of the body is called a secondary bone cancer.
Symptoms of secondary bone cancer may include
- Pain due to breakdown of the bone
- Weakened bones
- Raised blood calcium levels, which can cause dehydration, confusion, vomiting, abdominal pain and constipation
- Low levels of blood cells, causing anemia, an increased risk of infection, and bruising or bleeding
Tests for secondary bone cancer include a bone scan. You may also have an MRI scan, a PET scan and X-rays.
The aim of treatment is usually to control the cancer and any symptoms, and to prevent problems developing. This is called palliative treatment. Deciding about treatment can be difficult when you have an advanced cancer. You need to understand what the treatment can do for you. You may also want to think about your quality of life during treatment.
Treatment may include
- Hormone therapy(hormone treatment)
- Biological therapy
- Radiofrequency ablation(injecting bone cement into the spine)
Secondary bone cancer
Where a cancer starts is called the primary cancer. If some cells break away from the primary cancer they can move through the blood stream or lymph system to another part of the body, where they can form a new tumor. This is called a secondary cancer. Secondary cancers are also called metastases (pronounced met-ass-ta-sees).
The secondary cancer is made of the same type of cells as the primary cancer. So, for example, if your cancer started in your lung and has spread to your bones, the areas of cancer in the bone are made up of lung cancer cells. This is different from having a cancer that first started in the bone (a primary bone cancer). In that case, the cancer is made up of bone cells that have become cancerous. This is important because the primary cancer tells your doctor which type of treatment you need.
Research is going on all the time into improving treatments for secondary bone cancer and helping people to cope with symptoms.
How secondary bone cancer affects the bones
Bones are made of living tissue, which constantly changes in healthy bones. Specialized cells called osteoclasts break down old bone. Other cells called osteoblasts build new bone. This well controlled process keeps the rates of breakdown and growth in balance, so the bones stay healthy and strong.
Secondary bone cancers produce chemicals that interfere with the balance between these two types of cells. This damages the bones making them weaker and more likely to break. When these changes happen the bone may release calcium into the blood.
Secondary bone cancer can develop in any of the bones of the body
Symptoms of secondary bone cancer
Sometimes secondary cancers in the bone are picked up before they cause symptoms, during tests to diagnose your primary cancer. But sometimes the first symptoms people have are from the secondary cancer.
Symptoms can include
- Pain from breakdown of the bone – the pain is continuous and people often describe it as gnawing
- Backache, which gets worse despite resting
- Weaker bones – they can break more easily
- Raised blood calcium (hypercalcaemia), which can cause dehydration, confusion, vomiting, abdominal pain and constipation
- Low levels of blood cells – blood cells are made in the bone marrowand can be crowded out by the cancer cells, causing anemia, increased risk of infection, bruising and bleeding
Cancer in the spinal bones can cause pressure on the spinal cord. If it isn't treated, it can lead to weakness in your legs, numbness, paralysis and loss of bladder and bowel control (incontinence). This is called spinal cord compression. It is an emergency so if you have these symptoms, you need to contact your cancer specialist straight away or go to the accident and emergency department.
If you have cancer, it can be difficult not to worry that every new ache or pain means your cancer has spread.
Remember that aches and pains are common and may be a muscle strain or an everyday ache. If you have a new pain you should tell your doctor. They will investigate if it doesn’t seem to be getting better. Telling your doctor and getting treatment as soon as possible helps to avoid further problems with bone fractures or severe pain.
Tests to diagnose secondary bone cancer
The main test to check for secondary bone cancer is a bone scan. You can read about bone scans.
Other tests you may have include
- An MRI scan
- PET scan
Some people need a bone marrow test to check whether the cancer is changing the number of blood cells the bone marrow makes, but this is not common.
Treatment for secondary bone cancer
The aim of treatment is usually to control the cancer and symptoms. It can also prevent problems developing, such as raised calcium levels, pain and fracture.
Secondary bone cancer can’t usually be cured. But treatment can control it for some time and help to control symptoms. This is called palliative treatment.
Deciding about treatment
Deciding about treatment can be difficult when you have advanced cancer. You need to understand what treatment can do for you. You may also want to think about your quality of life while you are having treatment. All treatment will have some side effects. You also need to think about other factors that treatment involves, such as travelling to and from hospital. If you start treatment, you can stop whenever you want to if you are finding it too much to cope with.
Your doctor will be able to talk this through with you and you can ask questions. You may find it helpful to talk things over with a close relative or friend, or there may be a specialist nurse or counselor at the hospital with whom you can talk.
Your treatment will depend on a number of factors including
- Your type of primary cancer
- The treatment you have already had
- How many bones are affected by cancer
- Whether your cancer has spread to other parts of the body
- Your general health
Treatment will also depend on the symptoms you have.
- Pain can be reduced with radiotherapy, painkillers and other treatments
- Weak bones can be strengthened with surgery, bisphosphonates, a biological therapy called denosumab or radiotherapy
- Raised calcium in the blood can be treated with bisphosphonates and fluids
- Pressure on the spinal cord from cancer cells in the spine needs to be treated urgently with steroids, radiotherapy and sometimes surgery
- Low levels of blood cells can be treated with blood transfusionsor platelet transfusions.
Types of treatment for secondary bone cancer
You may have one or more of the following treatments for cancer that has spread to the bone.
Some cancers depend on hormones to survive and grow. So lowering hormone levels in the body can help to control them. This includes breast and prostate cancers. You may have hormone treatment for other types of cancer.
Hormone treatment may be tablets or injections. We have general information about hormone therapy, and we have specific information about hormone therapy for different types of cancer in our cancer type sections.
Radiotherapy treatment uses high energy waves similar to X-rays to kill cancer cells. Radiotherapy can help to control cancer growth and control pain. You usually have this as external radiotherapy. The photo shows an external radiotherapy machine.
For some cancers, internal radiotherapy using radioactive liquids called isotopes can work well. Doctors may suggest this if your cancer has spread to more than one bone. It works best for cancers that started in the prostate gland or the thyroid gland. You have an injection of a small amount of radioactive liquid, which the cancer cells in the bone take up. This gives a dose of radiotherapy to these areas. You can have radioisotope treatment more than once.
You will have some radioactivity in your body for a while after internal radiotherapy. But the total amount is extremely small and gets lower each day. Your radiotherapist or specialist nurse will let you know if there are any safety guidelines you need to follow after your treatment and how long you need to follow them for. This will depend on the dose of radioisotope you have had.
You can find out about radiotherapy for bone pain and internal radiotherapy using isotopes.
Chemotherapy uses cell killing drugs to kill cancer cells. Your doctor may suggest chemotherapy if hormone treatment is not an option or has stopped working. The type of chemotherapy you'll have depends on your type of primary cancer. You can find out more in the chemotherapy section for your type of cancer.
You can also read our general information about chemotherapy.
Biological therapies are treatments that act on processes in cells. Or these drugs may stop cancer cells telling each other to divide and grow.
Your doctor may suggest biological therapy if it is suitable for your particular type of primary cancer. There are many different types of biological therapy, including monoclonal antibodies and cancer growth blockers.
Denosumab is a type of monoclonal antibody that can help to strengthen bones and reduce the risk of fractures. It does this by helping to stop the bones being broken down by osteoclasts. You have denosumab as an injection just under your skin (subcutaneously).
Bisphosphonates are drugs that doctors use to slow down or prevent bone damage and lower calcium levels. You may hear them called bone hardening or bone strengthening treatment. You have bisphosphonates either through a drip or as tablets. There are a number of different types. Possible side effects include constipation and stomach ache.
You may have surgery to strengthen weakened bones. This is not a very common treatment. It includes having metal pins put in, or a joint replaced (such as a hip joint). Surgery can also be used to fix a fracture that has occurred in a weakened bone.
If you have cancer in your spine you may have rods put in to stabilise and strengthen it. You can find out about this treatment in the spinal cord compression section.
Radiofrequency ablation (RFA)
Radiofrequency ablation (RFA) kills cancer cells by heating them up. RFA is quite a specialized treatment and you may have to travel to a specialist center to have it.
Injecting bone cement into the spine
Your doctor may suggest injecting a special cement into the spine if
- Your cancer is in the bones of the spine and causing pain
- The spinal bones have collapsed
There are 2 ways of injecting bone cement into the spine. They are called vertebroplasty and kyphoplasty.
Pain control and supportive treatments
Many of the treatments above help to control pain by shrinking the tumor and reducing pressure on nerves or surrounding tissue. Most people start by taking painkillers. If you then have treatment that shrinks your bone secondaries, you may be able to reduce the amount of painkillers you take.
There are many different types of painkiller. If your pain is mild, paracetamol may help. If you have moderate or severe pain you will need stronger painkillers, including opioid painkillers such as morphine. You may need to take a combination of drugs. Anti-inflammatory medicines such as ibuprofen can help to control bone pain. An experienced doctor or nurse will be able to assess your pain and decide which type of painkiller and dose is best.
You may find it difficult to sleep because of pain or because of the cancer itself. This may make you feel tired and can make everyday tasks difficult. It can help if you allow yourself extra time to do things and let other people help when necessary.
You may also feel tired if your bone marrow is affected by the cancer. Your doctor may suggest blood tests to check your blood cell counts. You may have blood transfusions if your red blood cells are low.
If you have high calcium levels in your blood, you will have medicines called bisphosphonates as well as fluids through a drip to help flush the calcium out of your body.
Coping with secondary bone cancer
There is no set way of dealing with cancer that has spread. Support is available at the hospital and from cancer support groups. Getting the support you need can help you to cope.
Finding out that your cancer has spread is likely to bring up many different feelings. You may be frightened, angry, shocked or numb or all of these. Most people have already had treatment for a primary cancer and it can feel very unfair to have to cope with cancer a second time. Some people already have a secondary cancer when they are first diagnosed.
Finding out about your cancer and treatment options can help you to feel more in control and better able to cope. Try to give yourself time. It is usually easier to deal with one issue at a time rather than trying to sort everything out at once.
You will need to get information from your own specialist to understand what the diagnosis means for you. It depends on where the cancer first started and whether it has spread anywhere else. Your specialist can also tell you about treatment and how it may help. Support to help you cope is available at the hospital, from your PCP and specialist nurses, and from support groups or online forums.
Your hospital or cancer organizations can offer emotional support or practical help, such as dealing with money matters.
It is important that you feel as well as you possibly can. Ask your specialist, PCP or hospital nurse about referral to a symptom control nurse (sometimes called palliative care nurses or home care nurses). These specialist nurses can work with you and your doctor to help control your cancer symptoms and improve your physical well-being.
Most people are worried about their outlook (prognosis) when they have a secondary cancer. It is very difficult to say what will happen. Only your own doctors can guide you as they have all the information about your cancer. Even then, they can only give you a general idea. Your individual outlook depends on many factors including whether the cancer has spread to more than one part of your body, how quickly it is growing, and how it responds to treatment.
Your doctor may have told you that treatment is no longer working or is not possible. This can be a shock. It is likely that you will have all sorts of questions that are difficult to ask and also difficult to answer.
Common questions include
- How long do I have to live?
- How will I die?
- Will I have pain?
- What will happen to me?
It may help to write your questions down before you talk to your doctor or nurse.
It is common in any family for some people to want to ask difficult questions and some not to want to. It is helpful to respect each person's way of dealing with things and give each other space to talk if you want to. This may mean that you need to give your doctor permission to talk to your next of kin or other family members alone. If you are a relative, you may need to give the person with cancer the space to talk to the doctor on their own.