What Is Bone Cancer?
Bone is the framework that supports the body. Most bones are hollow. Bone marrow is the soft tissue inside hollow bones. The bone itself is very hard and strong. At each end of the bone is a softer bone-like tissue called cartilage that acts as a cushion between bones. The outside of the bone is covered with a layer of fibrous tissue.
The bone itself is made up of 2 kinds of cells. Osteoblasts are cells that form the bone. Osteoclasts are cells that dissolve bone. Although we think that bone does not change, the truth is that it is very active. New bone is always forming and old bone dissolving.
The marrow of some bones is made up only of fatty tissue. In other bones the marrow is a mixture of fat cells and blood-forming cells. These blood-forming cells make red blood cells, white blood cells, and platelets.
All of these parts of bone can develop into cancer.
Types of Bone Cancers
Most of the time when someone is told they have bone cancer, the doctor is talking about a cancer that started somewhere else and then spread to the bone. This is called metastatic cancer and can happen to people with advanced breast cancer, prostate cancer, and lung cancer, as well as many others. When these cancer cells are looked at under a microscope, they look like the cancer cells that they came from. If someone has lung cancer that has spread to the bone, the cells there will look and act like lung cancer cells and they will be treated the same way.
To learn more about cancer that has spread to the bones, please see “Bone Metastases” as well as the document on the place where the cancer started (“Breast Cancer,” “Prostate Cancer,” etc.)
Other kinds of cancers that are sometimes called “bone cancers” start in the bone marrow—in the blood-forming cells. The most common of these is multiple myeloma. Certain lymphomas (which more often start in lymph nodes) and all leukemias start in bone marrow. You can get more information about all of these types of cancers from the American Cancer Society.
The main type of true bone cancers are called sarcomas. A sarcoma is a cancer that starts in connective tissue such as bone, muscle, tendons, ligaments, or some other tissues in the body.
Primary Bone Tumors
There are several different types of bone tumors. Their names are based on the bone or tissue that is involved and the kind of cells that make up the tumor. Some are cancerous (malignant). Others are not cancerous (benign). Most bone cancers are called sarcomas.
Benign bone tumors do not spread to other tissues and organs. They can usually be cured by surgery. This information does not cover benign bone tumors.
Cancerous Bone Tumors
Osteosarcoma: Osteosarcoma is cancer of the bone itself. It most often occurs in young people between the ages of 10 and 30. But about 10% of cases occur in people in their 60s and 70s. This cancer is rare during middle age. More males than females get this cancer. These tumors start most often in bones of the arms, legs, or pelvis.
Chondrosarcoma: This is a cancer of cartilage cells and is the second most common true bone cancer. Chondrosarcoma is not often found in people younger than 20. After age 20, the risk of this cancer keeps on rising until about age 75. It occurs in men and women at about the same rate.
Cartilage is softer than bone but more firm than most other tissues. Ears are mainly cartilage. Cartilage is actually the tissue from which most bones form. It is mainly found at the end of long bones and at the place in the chest where the ribs meet the breastbone. Chondrosarcoma most often starts in cartilage of the pelvis, leg or arm, but it can start in many other places as well.
Chondrosarcomas are given a grade, depending on how fast-growing they are. A lower grade means the cancer is not likely to spread while a high grade means it is more likely to spread. Most are low grade. There are also other differences among chondrosarcomas that can be seen under a microscope which help to predict the response to treatment and outlook for survival.
Ewing tumor: This cancer is named after Dr. James Ewing, the doctor who first described it in 1921. Unlike osteosarcoma, Ewing tumors form in the hollow part of the bone. This cancer usually appears in children and teenagers. It is not common in adults over 30 years old.
Fibrosarcoma and malignant fibrous histiocytoma: These cancers usually start in the soft tissues around bones (such as ligaments, tendons, fat, and muscle) rather than the bone itself. They usually occur in older and middle-aged adults. These cancers most often affect bones of the legs, arms, or jaw.
Giant cell tumor of bone: This type of bone tumor has both benign and malignant forms. Only about 10% of giant cell bone tumors are cancerous and spread to other parts of the body. But they often come back after surgery. When they do come back after surgery they are more likely to spread to other parts of the body. These tumors often affect the arm or leg bones of young and middle-aged adults.
Chordoma: This tumor usually occurs in the base of the skull and bones of the spine. It is found most often in adults older than 30 years, and is about twice as common in men than in women. Chordomas tend to grow slowly and usually do not spread to other parts of the body, but they often come back in the same place if they are not removed completely. When they do spread, lymph nodes, the lungs, and the liver are the most common places.
What Causes Bone Cancer?
The exact cause of most bone cancers is not known. But we do know that certain risk factors are linked to this disease. A risk factor is something that increases a person's chance of getting a disease. Some risk factors, such as smoking, can be controlled. Others, like a person’s age or race, can’t be changed. But having a risk factor, or even several, does not mean that you will get cancer. Most people with bone cancer do not have any apparent risk factors.
The risk factors for bone cancer are often linked to having had other diseases, treatments for other diseases, or age. The following conditions can slightly increase the risk of bone cancer. If you have any of these, you should ask your doctor for more information.
- Li-Fraumeni syndrome
- Rothmund-Thompson syndrome
- Retinoblastoma (a rare eye cancer of children)
- Paget disease
- Multiple exostoses (multiple osteochondromas)
People who have been treated with radiation for an earlier cancer have a higher risk of getting bone cancer later. Being treated at a younger age and being treated with high doses of radiation increase the risk of bone cancer.
Bone cancer has been reported in a few people who have had bone marrow (stem cell) transplantation.
There is no evidence to show that an injury to a bone can lead to bone cancer.How Is Bone Cancer Found?
For some types of cancer there are tests that can find the cancer early, before it causes any symptoms. But right now, there are no special tests to find bone cancer early. The best approach is to report any symptoms promptly to the doctor. In most cases a biopsy will be done to see if bone cancer is really present (see below).
Pain: Pain in a bone is the most common symptom of bone cancer. At first, the pain is not constant and may be worse at night or when the bone is used. As the cancer grows, the pain will be there all the time.
Swelling: Swelling in the area of the pain may not happen until weeks later. Depending on the where the tumor is found, it may be possible to feel a lump.
Breaks (fractures): Although the cancer may weaken the bone it grows in, the bones do not usually break.
General symptoms: Problems such as weight loss and tiredness (fatigue) may mean that the cancer has spread. If it has spread to organs inside the body, there may be other symptoms as well. For example, if the cancer spreads to the lung, the person may have trouble breathing.
Bone pain and swelling are usually due to other problems, like an injury or arthritis. Most people with these symptoms do not have cancer. But doctors should test for cancer if signs and symptoms don’t go away and can’t be explained.
Doctors can use several methods to find bone cancer. Symptoms, a physical exam, imaging tests, and blood tests may all suggest bone cancer. But in most cases, a biopsy is needed to make sure since other diseases can cause the same symptoms. See below to learn more about these tests.
X-rays: Most of the time, bone cancer will show up on x-rays of the bone. The radiologist (a doctor who specializes in reading x-rays) can often tell if a tumor is cancer by the way it looks on the x-ray.
CT scans (computed tomography): In this test, many x-rays of the body are taken from different angles. These images are combined by a computer to produce cross-sectional pictures of internal organs. Before the x-ray is taken, a harmless dye may be injected into a vein to highlight details. Some people have a reaction to the dye (hives, flushing, trouble breathing). Be sure to tell the doctor if you have ever had problems with contrast dye. CT scans can also be used to guide a biopsy needle into a tumor or mass.
CT scans take longer than regular x-rays. You will need to lie still on a table as the part of your body being scanned is placed within the scanner, a doughnut-shaped machine that completely surrounds the table. The test is painless, but you may find it hard to hold still for minutes at a time.
MRI (magnetic resonance imaging): MRI scans use radio waves and strong magnets instead of x-rays. MRI pictures look a lot like those of a CT scan, but MRIs are more detailed. A contrast dye might be injected, just as with CT scans, but is used less often.
MRI scans are the best test for outlining a bone tumor. They are also useful for looking at the brain and spinal cord.
MRI scans take longer than CT scans, often up to an hour. And you have to be placed inside a tube, which can upset some people. The machine makes a thumping noise but many places will provide headphones with music to block this out.
Radionuclide bone scan: A bone scan helps show if cancer has spread to other bones. It can also show how much the cancer has damaged the bone. In this test, the patient is injected with a radioactive material. (The radioactivity is very low and causes no long-term effects.) The material is attracted to diseased bone cells throughout the body. A special camera takes a picture. The picture shows the diseased bone as dense, gray to black areas, called "hot spots." These areas may be cancer. But arthritis, infection, and other bone diseases can look much the same. The doctor may use other tests or biopsies to find out for sure what is causing the hot spots.
PET scan (positron emission tomography): PET scans involve injecting radioactive glucose (a type of sugar), which can be detected by a special camera. Cancer cells absorb high amounts of the sugar because they are very active. PET can be more helpful than several x-rays because it scans the whole body. It can sometimes show whether a tumor is cancerous or is benign. It is sometimes combined with a CT scan.
A biopsy involves taking a tiny piece of the tumor and looking at it under a microscope. Doctors study the piece to see whether it is cancer. The biopsy can also help tell if it is a primary or a secondary bone cancer. The surgeon doing the biopsy needs to have experience diagnosing and treating bone tumors. Mistakes at this point can lead to removing too much tissue, which can limit options for saving an arm or leg (limb-sparing surgery).
There are 2 different types of biopsies, the needle biopsy and the surgical bone biopsy:
Needle biopsy: This can be done with a thin (fine) or a thick needle. The fine needle biopsy removes a small amount of fluid and tissue fragments. The doctor can aim the needle at an area near the surface of the body. If the tumor is deep inside the body, the needle can be guided by a CT scan. A thick needle biopsy is called a core biopsy. With a core biopsy, the doctor removes a small cylinder of tissue. In both cases, the skin is numbed before the biopsy is done.
Surgical bone biopsy: First the area around the tumor will be numbed, or in some cases, the patient may have general anesthesia (be put into a deep sleep). Then the surgeon cuts through the skin to remove a small part of a large tumor.How Is Bone Cancer Treated?
This information represents the views of the doctors and nurses serving on the American Cancer Society's Cancer Information Database Editorial Board. These views are based on their interpretation of studies published in medical journals, as well as their own professional experience.
The treatment information in this document is not official policy of the Society and is not intended as medical advice to replace the expertise and judgment of your cancer care team. It is intended to help you and your family make informed decisions, together with your doctor.
Your doctor may have reasons for suggesting a treatment plan different from these general treatment options. Don't hesitate to ask him or her questions about your treatment options.
There has been great progress in the treatment of bone cancer during the last 30 years. In the 1960s the only treatment available was amputation. Now, because of new methods, amputation isn’t needed most of the time
Chemotherapy
Chemotherapy refers to the use of drugs to kill cancer cells. Usually the drugs are given into a vein or by mouth. Once the drugs enter the bloodstream, they reach throughout the body. This treatment is useful for cancer that has spread to other organs. Except for Ewing’s sarcoma and osteosarcoma, chemotherapy is seldom used for bone cancer unless it has spread.
Before giving chemotherapy drugs, your doctor will check your lab test results to be sure your liver, kidney, and bone marrow (which produces the cells in the blood) are working well.
Chemotherapy kills cancer cells, but it will also damage some normal cells. This can cause some side effects. These will depend on the type of drugs given, the amount taken, and how long treatment lasts. These side effects could include the following:
- nausea and vomiting
- loss of appetite
- hair loss (the hair grows back after treatment ends)
- mouth sores
- increased chance of infection (from a shortage of white blood cells)
- bleeding or bruising after small cuts or injuries (from a shortage of platelets)
- tiredness or shortness of breath (from low red blood cell counts)
Most side effects go away once treatment stops. There are also treatments for many of the side effects of chemotherapy. For example, certain drugs can help with nausea and vomiting.
Surgery
Surgery for bone cancer includes the biopsy done to find the cancer and the surgery done to remove it. It is very important that the biopsy and surgical treatment be planned together. If possible, the same surgeon at a cancer center should do both the biopsy and the surgical treatment.
The goal of surgery is to remove the tumor and at least about 1 inch (2 to 3 centimeters) of the tissue around it. If the cancer is in one place but cannot be removed with surgery (for example, at the base of the skull, or in the spine or pelvis), then a cure is not likely, even if it treated with chemotherapy.
The surgery can be either limb-salvage (or limb-sparing, which removes the cancer without amputation) or amputation (removing the cancer and all or part of an arm or leg).
Limb-salvage surgery is very complex. The surgeons who do it must have special skills and experience. The bone that is removed is replaced with a bone graft from donors or with a rod made of metal or other materials. This rod is called an endoprosthesis (meaning internal prosthesis).
Anywhere from 5 to 8 patients out of 10 might be able to have their limbs spared. Ask the surgeon to explain the best way to remove the cancer and keep as much use of the arm or leg as possible. Because the rods or grafts are often used in growing children, they are designed to grow with the child. They can be made longer without any extra surgery. Some have tiny devices in them that can lengthen the implant when needed to make room for growth.
Problems with this approach can include infection and grafts or rods that become loose or broken. Patients may also need more surgery during the next 5 years, and some may need an amputation after all. It takes an average time of 1 year for patients to learn to walk again after such surgery on a leg. Rehabilitating the patient is more intense than after amputation. If the patient does not take part in the rehabilitation program, the salvaged arm or leg may become useless.
Amputation may be the only option for some patients. If there is a large tumor that extends into the nerves and/or the blood vessels, it may not be possible to save the limb. Surgery is planned so that muscles and the skin will form a cuff around the end of the arm or leg. This cuff will fit into the end of an artificial limb (called a prosthesis). With proper physical therapy the person is often walking on his/her own 3 to 6 months after leg amputation.
Sometimes if the leg must be removed at mid-thigh, the lower leg and foot are turned and attached to the thigh bone. The ankle then serves as a knee joint. This type of surgery is called rotationplasty. Of course, the person will need an artificial limb to extend the leg.
If the cancer is in the upper arm, the tumor may be removed and the lower arm reattached so the person has an arm that works, though it is much shorter.
If the cancer is in the lower jaw bone, the whole lower half of the jaw may be removed and later replaced with bones from other parts of the body.
After Surgery
The time after surgery may be the hardest part. The patient (and parents) need to meet with a rehabilitation specialist to learn about all the options.
Both limb-sparing and amputation surgeries have their own problems as well as unique benefits. If a limb was removed, the person must learn to deal with the artificial limb. This is especially hard for growing children where the device needs to be changed to keep up with their growth. The limb-sparing method, although more acceptable than amputation, can lead to more complications.
It turns out that, in terms of how people react and quality of life, there is little difference in the approaches. Perhaps the biggest problem has been for teen-agers who are afraid of the social effects of their operation. These feelings and concerns are very important and support and encouragement are needed for all patients and their families.
Treatment of metastasis: Treatment to remove bone cancer metastases to the lungs must be planned very carefully. Removing all the lung metastases likely gives the patient the only chance for cure. But sometimes all the metastases can’t be removed. They might be too big or too close to large blood vessels. If the patient is not otherwise in good health, he or she may not be able to withstand the stress of surgery.
For some types of bone tumors such as giant cells tumors a method called curettage might be used. This involves scooping out the tumor from the bone, without removing a section of the bone. In some cases, after most of the tumor has been removed, the surgeon will treat the nearby bone tissue to kill any remaining tumor cells. The hole left behind is filled in with a bone graft or an artificial material.
Radiation Therapy
Radiation therapy uses high-energy radiation to kill cancer cells. External beam radiation uses radiation delivered from outside the body. The beam is focused on the cancer. This is the type of radiation that has been tried as a treatment for bone cancer. But bone cancers are not easily killed by radiation. Radiation does not play a major role in the treatment of most types of bone tumors. It may be useful, though, in some cases where the tumor cannot be completely removed by surgery. It is also helpful in controlling symptoms like pain and swelling if the cancer has come back or if surgery is not possible.
Treatment of Specific Bone Cancers
Chondrosarcoma: Treatment consists mainly of the biopsy and then surgery to remove the tumor. If the tumor can’t be totally removed, high-dose radiation therapy may be used. If the cancer has spread to a few places in the lung, those metastases may be removed.
If the tumor is in a place where it can’t be removed (for example, the skull) it is sometimes treated with curettage and cryosurgery (a treatment that uses freezing to kill cancer cells) or with radiation therapy.
Malignant fibrous histiocytoma: MFH is treated using the same approach as for osteosarcoma. The usual treatment plan starts with chemotherapy. This shrinks the tumor and makes it easier to remove. Next, surgery may be done to remove the tumor and bone close to it. After that, the bone may be reconstructed with a bone graft or metal rod. Amputation is done less often now than in the past. In some cases, chemotherapy is also given after surgery.
Fibrosarcoma: Surgery is the main treatment for this kind of cancer. If the tumor cannot be removed completely, radiation therapy is used instead of or along with surgery. Radiation is also used if the cancer returns after surgery.
Giant cell tumor of bone: These are treated mainly with surgery. The extent of surgery can vary, and is influenced by the location of the tumor. Another option that is becoming more common is curettage, sometimes followed by applying extreme hot or cold temperatures to kill any remaining cancer cells. In some cases, radiation might be used.
If there are only a few metastatic tumors in the lungs, it may be possible to remove them surgically. Metastases can also be treated with radiation.
Chordoma: This tumor usually occurs in the base of the skull and bones of the spine. Removing the cancer completely would be best, but it might not be possible. If some of the tumor remains after surgery, radiation is often used but must be aimed carefully. Chemotherapy is sometimes used if a chordoma has spread widely. Long-term follow-up is important because these tumors can come back, even 10 or more years after treatment.
The outlook for people with primary bone cancer varies greatly, depending on the specific type of cancer and how far it has spread. If you have questions about your own treatment plan, chances of a cure, or how long you might survive, talk with your cancer care team.
