Cancer starts when cells in the body begin to grow out of control. Cells in nearly any part of the body can become cancer, and can spread to other areas of the body. To learn more about how cancers start and spread, see What Is Cancer?

Osteosarcoma (also called osteogenic sarcoma) is the most common type of cancer that starts in the bones. The cancer cells in these tumors look like early forms of bone cells that normally help make new bone tissue, but the bone tissue in an osteosarcoma is not as strong as that of normal bones.

Most osteosarcomas occur in children and young adults. Teens are the most commonly affected age group, but osteosarcoma can develop at any age. (For information about the differences between childhood cancers and adult cancers, see Cancer in Children.)

Where does osteosarcoma start?

In children and young adults, osteosarcoma usually starts in areas where the bone is growing quickly, such as near the ends of the leg or arm bones:

• Most tumors develop in the bones around the knee, either in the distal femur (the lower part of the thigh bone) or the proximal tibia (the upper part of the shinbone).
• The upper arm bone close to the shoulder (proximal humerus) is the next most common site.

Still, osteosarcoma can develop in any bone, including the bones of the pelvis (hips), shoulder, and jaw. This is especially true in older adults.

Subtypes of osteosarcoma

Based on how the cells look under the microscope, osteosarcomas can be classified as high grade, intermediate grade, or low grade. The grade of the tumor tells doctors how likely it is that the cancer will grow and spread to other parts of the body.

High-grade osteosarcomas

These are the fastest growing types of osteosarcoma. When seen with a microscope, they do not look like normal bone and have many cells in the process of dividing into new cells. Most osteosarcomas that occur in children and teens are high grade. There are many types of high-grade osteosarcomas (although the first 3 are the most common).

• Osteoblastic
• Chondroblastic
• Fibroblastic
• Small cell
• Telangiectatic
• High-grade surface (juxtacortical high grade)

Other high-grade osteosarcomas include:

• Pagetoid: a tumor that develops in someone with Paget disease of the bone
• Extraskeletal: a tumor that starts in a part of the body other than a bone (but still makes bone tissue)
• Post-radiation: a tumor that starts in a bone that had once been treated with radiation

Intermediate-grade osteosarcomas

These uncommon tumors fall between high-grade and low-grade osteosarcomas. (They are usually treated the same way as low-grade osteosarcomas.)

• Periosteal (juxtacortical intermediate grade)

Low-grade osteosarcomas

These are the slowest-growing osteosarcomas. The tumors look more like normal bone and have few dividing cells when seen with a microscope.

• Parosteal (juxtacortical low grade)
• Intramedullary or intraosseous well differentiated (low-grade central)

The grade of the tumor plays a role in determining its stage and the type of treatment used. For more on staging, see Osteosarcoma Stages.

Other types of bone tumors

Several other types of tumors can start in the bones.

Malignant (cancerous) bone tumors

Ewing tumors are the second most common bone cancer in children. They are described in Ewing Family of Tumors.

Most other types of bone cancers are usually found in adults and are rare in children. These include:

• Chondrosarcoma (cancer that develops from cartilage)
• Malignant fibrous histiocytoma (MFH) of bone, also known as undifferentiated pleomorphic sarcoma of bone
• Fibrosarcoma
• Chordoma
• Malignant giant cell tumor of bone

For more information on these cancers, see Bone Cancer.

Many types of cancer that start in other organs of the body, especially cancers in adults, can spread to the bones. These are sometimes referred to as metastatic bone cancers, but they are not true bone cancers. For example, prostate cancer that spreads to the bones is still prostate cancer and is treated like prostate cancer. For more information, see Bone Metastasis.

Benign (non-cancerous) bone tumors

Not all bone tumors are cancer. Benign bone tumors do not spread to other parts of the body. They are usually not life threatening and can often be cured by surgery. There are many types of benign bone tumors, including:

• Osteoma
• Chondroma
• Osteochondroma
• Eosinophilic granuloma of bone
• Non-ossifying fibroma
• Enchondroma
• Benign giant cell tumor of bone
• Lymphangioma

Survival rates are often used by doctors as a standard way of discussing the prognosis (outlook) of a person with a certain type and stage of cancer. These numbers tell you what portion of people with the same type and stage of cancer are still alive a certain amount of time (usually 5 years) after they were diagnosed. They can’t tell you exactly what will happen with any person, but they may help give you a better understanding about how likely it is that treatment will be successful. Some people find survival rates helpful, but some people might not.

What is a 5-year survival rate?

Statistics on the outlook for a certain type and stage of cancer are often given as 5-year survival rates. The 5-year survival rate is the percentage of people who live at least 5 years after being diagnosed with cancer. For example, a 5-year survival rate of 70% means that an estimated 70 out of 100 people who have that cancer are still alive 5 years after being diagnosed. 

Of course, many people live much longer than 5 years (and many are cured).

But remember, the 5-year relative survival rates are estimates – each person’s outlook can vary based on a number of factors specific to them.

Cancer survival rates don’t tell the whole story

Survival rates are often based on previous outcomes of large numbers of people who had the disease, but they can’t predict what will happen in any person’s case. There are a number of limitations to remember:

• The numbers below are among the most current available. But to get 5-year survival rates, doctors have to look at people who were treated at least 5 years ago. As treatments are improving over time, people who are now being diagnosed with osteosarcoma may have a better outlook than these statistics show.
• These statistics are based on the extent of the cancer when it was first diagnosed. They do not apply to cancers that later come back or spread, for example.
• The outlook for people with osteosarcoma varies by the stage (extent) of the cancer – in general, the survival rates are higher for people with earlier stage cancers. But many other factors can affect a person’s outlook, such as the subtype and location of the osteosarcoma and how well the cancer responds to treatment. 

Your (child’s) doctor can tell you how the numbers below may apply, as he or she is familiar with your (child’s) particular situation.

Survival rates for localized osteosarcomas

The 5-year survival rate for people with localized osteosarcoma is in the range of 60% to 80%. These cancers are more likely to be cured if they are resectable -- that is, if all of the visible tumor can be removed (resected) by surgery. (For high-grade osteosarcomas that can be resected completely, chemotherapy is still an essential part of treatment. Without it, the cancer is still very likely to come back.)

Survival rates for metastatic osteosarcomas

If the osteosarcoma clearly has already spread when it is first found, the 5-year survival rate is about 15% to 30%. The survival rate is closer to 40% if the cancer has spread only to the lungs (as opposed to having reached other organs), or if all of the tumors (including metastases) can be removed with surgery.

Other factors that may affect prognosis

As noted above, factors other than the stage of the cancer can also affect survival rates. For example, factors that have been linked with a better prognosis include:

• Being younger (child or teen, as opposed to adult)
• Being female
• The tumor being on an arm or leg (as opposed to the hip bones)
• The tumor(s) being completely resectable
• Normal blood alkaline phosphatase and LDH levels
• The tumor having a good response to chemotherapy

Osteosarcomas are usually found because of signs or symptoms a person is having, which prompts a visit to a doctor. If a bone tumor is suspected, exams and tests will be needed to find out for sure.

Medical history and physical exam

If a person has signs or symptoms that suggest they might have a tumor in or around a bone, the doctor will want to take a complete medical history to find out more about the symptoms.

A physical exam can provide information about a possible tumor, as well as other health problems. For example, the doctor may be able to see or feel an abnormal mass.

The doctor may also look for problems in other parts of the body. When people (especially adults) have cancer in the bones, it’s often the result of cancer that started somewhere else and then spread to the bones.

If the doctor suspects a person could have osteosarcoma (or another type of bone tumor), more tests will be done. These might include imaging tests, biopsies, and/or lab tests.

Imaging tests

Imaging tests use x-rays, magnetic fields, or radioactive substances to create pictures of the inside of the body. Imaging tests might be done for a number of reasons, including:

• To help find out if a suspicious area might be cancer
• To help determine if a cancer might have started in another part of the body
• To learn how far cancer has spread
• To help determine if treatment is working
• To look for signs that the cancer might have come back

Patients who have or might have osteosarcoma will have one or more of these tests.

Bone x-ray

This is often the first test done if a bone tumor is suspected. Doctors can often recognize a bone tumor such as osteosarcoma based on plain x-rays of the bone. But other imaging tests might be needed as well.

Even if results of an x-ray strongly suggest a person has osteosarcoma, a biopsy will still be needed to confirm that it is cancer rather than some other problem, such as an infection.

Magnetic resonance imaging (MRI) scan

MRI scans create detailed images of soft tissues in the body using radio waves and strong magnets instead of x-rays, so no radiation is involved. A contrast material called gadolinium may be injected into a vein before the scan to better see details.

An MRI scan is often done to get a more detailed look at a bone mass seen on an x-ray. MRI scans can usually show if the mass is likely to be a tumor, an infection, or some type of bone damage from other causes.

MRI scans can also help show the exact extent of a tumor, as they can show the marrow inside bones and the soft tissues around the tumor, including nearby blood vessels and nerves. Sometimes, the MRI can help find small bone tumors several inches away from the main tumor (called skip metastases). Knowing the extent of an osteosarcoma is very important when planning surgery.

An MRI scan usually gives better details than a CT scan (described below).

Computed tomography (CT) scan

A CT scan combines many x-ray pictures to make detailed cross-sectional images of parts of the body. If a bone x-ray shows a tumor, CT scans are sometimes used to see if the tumor has grown into nearby muscle, fat, or tendons, although MRI is often better for this.

A CT scan of the chest is often done to look for spread of the cancer to the lungs. CT scans may also be done to look for the spread of the cancer to other parts of the body.

Chest x-ray

This test is sometimes done to see if cancer has spread to the lungs. It can find larger tumors, but it is not as good as a CT scan for spotting smaller tumors. If a CT scan of the chest is done, a chest x-ray probably won’t be needed.

Bone scan

A bone scan can help show if a cancer has spread to other bones, and is often part of the workup for people with osteosarcoma. This test is useful because it can show the entire skeleton at once. (A positron emission tomography [PET] scan, described below, can often provide similar information, so a bone scan might not be needed if a PET scan is done.)

For this test, a small amount of low-level radioactive material is injected into the blood and travels to the bones. A special camera can detect the radioactivity and create a picture of the skeleton.

Areas of active bone changes appear as “hot spots” on the skeleton because they attract the radioactivity. Hot spots may suggest areas of cancer, but other bone diseases can also cause the same pattern. To make an accurate diagnosis, other tests such as plain x-rays, MRI scans, or even a bone biopsy might be needed.

Positron emission tomography (PET) scan

For a PET scan, a form of radioactive sugar (known as FDG) is injected into the blood. Because cancer cells in the body are growing quickly, they absorb large amounts of the sugar. A special camera can then create a picture of areas of radioactivity in the body. The picture is not detailed like a CT or MRI scan, but it provides useful information about the whole body.

PET scans can help show the spread of osteosarcomas to the lungs, other bones, or other parts of the body, and can also help in seeing how well the cancer is responding to treatment.

Some newer machines can do a PET and CT scan at the same time (PET/CT scan). This lets the doctor compare areas of higher radioactivity on the PET scan with the more detailed appearance of that area on the CT scan.

To learn more about this and other imaging tests, see Imaging (Radiology) Tests.

Biopsy

The results of imaging tests might strongly suggest that a person has some type of bone cancer, but a biopsy (removing some of the tumor for viewing under a microscope and other lab testing) is the only way to be certain. A biopsy is also the best way to tell osteosarcoma from other types of bone cancer.

If the tumor is in a bone, it is very important that an orthopedic surgeon experienced in treating bone tumors does the biopsy. Whenever possible, the biopsy and surgical treatment should be planned together, and the same surgeon should do both. Proper planning of the biopsy can help prevent later complications and might reduce the amount of surgery needed later on.

There are 2 main types of biopsies.

Needle biopsy

For these biopsies, the doctor uses a hollow needle to remove a small sample of the tumor. The biopsy is usually done with local anesthesia, where numbing medicine is injected into the skin and other tissues over the biopsy site. In some cases, sedation or general anesthesia (where the patient is asleep) may be needed.

Often, the doctor can aim the needle by feeling the suspicious area if it's near the surface of the body. If the tumor can’t be felt because it's too deep, the doctor can guide the needle into the tumor using an imaging test such as a a CT scan. This is called a CT-guided needle biopsy.

Core needle biopsy: In a core needle biopsy, the doctor uses a large, hollow needle to remove a small cylinder of tissue from the tumor.

Fine needle aspiration (FNA) biopsy: For an FNA biopsy, the doctor uses a very thin needle attached to a syringe to withdraw (aspirate) a small amount of fluid and some cells from the tumor. This type of biopsy is rarely used to diagnose a bone tumor.

Surgical (open) biopsy

In an open biopsy, the surgeon cuts through the skin, exposes the tumor, and then cuts out a piece of it. These biopsies are usually done in an operating room with the patient under general anesthesia (in a deep sleep). They can also be done using a nerve block, which numbs a large area of the body.

This type of biopsy must be done by an expert in bone tumors, or it could result in problems later on. For example, if the tumor is on the arm or leg, the chances of saving the limb might be lowered. If possible, the incision in the skin used in the biopsy should be lengthwise along the arm or leg because this is the way the incision will be made during the operation to remove the cancer. The entire scar of the original biopsy will also have to be removed, so making the biopsy incision this way lessens the amount of tissue that needs to be removed later on.

Lab tests

Testing the biopsy samples

All samples removed by biopsy are sent to a pathologist (a doctor specializing in lab tests) to be looked at with a microscope. Tests looking for chromosome or gene changes in the tumor cells might also be done. These tests can help tell osteosarcoma from other cancers that look like it under the microscope, and they can sometimes help predict whether the osteosarcoma is likely to respond to therapy.

If osteosarcoma is diagnosed, the pathologist will assign it a grade, which is a measure of how quickly the cancer is likely to grow and spread, based on how its cells look. Cancers that look somewhat like normal bone tissue are described as low grade, while those that look very abnormal are called high grade. For more on grading, see Osteosarcoma Stages.

Blood tests

Blood tests are not needed to diagnose osteosarcoma, but they may be helpful once a diagnosis is made. For example, high levels of chemicals in the blood such as alkaline phosphatase and lactate dehydrogenase (LDH) can suggest that the osteosarcoma may be more advanced than it appears.

Other tests such as blood cell counts and blood chemistry tests are done before surgery and other treatments to get a sense of a person’s overall health. These tests are also used to monitor a person’s health while they are getting chemotherapy.

Finding out that you or a loved one has cancer can be overwhelming. Coping with Cancer describes the emotions and concerns you might face and things you can do to help work through them.

 

After someone is diagnosed with osteosarcoma, doctors will try to figure out if it has spread, and if so, how far. This process is called staging. The stage of a cancer describes how much cancer is in the body. It helps determine how serious the cancer is and how best to treat it. Doctors also use a cancer's stage when talking about survival statistics.

The stage of an osteosarcoma is based on the results of physical exams, imaging tests, and any biopsies that have been done, which are described in Tests for Osteosarcoma.

A staging system is a standard way for the cancer care team to sum up the extent of the cancer. When trying to figure out the best course of treatment, doctors often use a simple system that divides osteosarcomas into 2 groups: localized and metastatic. Doctors can also use more formal staging systems (see below) to describe the extent of an osteosarcoma in more detail.

Osteosarcoma staging can be confusing. If you have any questions about the stage of the cancer, ask someone on your cancer care team to explain it to you in a way you understand.

Localized osteosarcoma

A localized osteosarcoma is seen only in the bone it started in and possibly the tissues next to the bone, such as muscle, tendon, or fat.

About 4 out of 5 osteosarcomas appear to be localized when they are first found. But even when imaging tests don’t show that the cancer has spread to distant areas, most patients are likely to have very small areas of cancer spread that can’t be detected with tests. This is why chemotherapy is an important part of treatment for most osteosarcomas. If it isn’t given, the cancer is more likely to come back after surgery.

Doctors further divide localized osteosarcomas into 2 groups:

• Resectable cancers are those in which all of the visible tumor can be removed by surgery.
• Non-resectable (or unresectable) osteosarcomas can’t be removed completely by surgery.

Metastatic osteosarcoma

A metastatic osteosarcoma has clearly spread to other parts of the body. Most often it spreads to the lungs, but it can also spread to other bones, the brain, or other organs.

About 1 out of 5 osteosarcomas has spread at the time of diagnosis. These cancers are harder to treat, but some can be cured if the metastases can be removed by surgery. The cure rate for these cancers improves markedly if chemotherapy is also given.

Musculoskeletal Tumor Society (MSTS) Staging System

A system commonly used to stage osteosarcoma is the MSTS system, also known as the Enneking system. It is based on 3 key pieces of information:

• The grade (G) of the tumor, which is a measure of how likely it is to grow and spread, based on how it looks under the microscope. Tumors are either low grade (G1) or high grade (G2). Low-grade tumor cells look more like normal cells and are less likely to grow and spread quickly, while high-grade tumor cells look more abnormal.
• The extent of the primary tumor (T), which is classified as either intracompartmental (T1), meaning it has basically remained within the bone, or extracompartmental (T2), meaning it has extended beyond the bone into other nearby structures.
• If the tumor has metastasized (M), which means it has spread to nearby lymph nodes (bean-sized collections of immune system cells) or other organs. Tumors that have not spread to the lymph nodes or other organs are considered M0, while those that have spread are M1.

These factors are combined to give an overall stage, using Roman numerals from I to III. Stages I and II are further divided into A for intracompartmental tumors or B for extracompartmental tumors.

Stage	Grade	Tumor	Metastasis
IA	G1	T1	M0
IB	G1	T2	M0
IIA	G2	T1	M0
IIB	G2	T2	M0
III	G1 or G2	T1 orT2	M1

In summary:

• Low-grade, localized tumors are stage I.
• High-grade, localized tumors are stage II.
• Metastatic tumors (regardless of grade) are stage III.

The TNM staging system

Another system sometimes used to stage bone cancers (including osteosarcomas) is the American Joint Commission on Cancer (AJCC) TNM system. This system is based on 4 key pieces of information:

• T describes the size of the main (primary) tumor and if it appears in different areas of the bone.
• N describes the extent of spread to nearby (regional) lymph nodes. Bone tumors rarely spread to the lymph nodes.
• M indicates if the cancer has metastasized (spread) to other organs of the body. (The most common sites of spread are to the lungs or other bones.)
• G stands for the grade of the tumor, which describes how the cells look under a microscope. Low-grade tumor cells look more like normal cells and are less likely to grow and spread quickly, while high-grade tumor cells look more abnormal.

Numbers after T, N, M, and G provide more details about each of these factors.

Once the T, N, and M categories and the grade of the bone cancer have been determined, the information is combined into an overall stage. These stages (which are different from those of the MSTS system) are described by Roman numerals from I to IV (1 to 4), and are sometimes divided further. For more detailed information on the AJCC TNM staging system for bone cancers, see Bone Cancer Stages.

Osteosarcomas are usually found because of the symptoms they are causing.

Pain and swelling

Pain in the affected bone (usually around the knee or in the upper arm) is the most common symptom of osteosarcoma. At first, the pain might not be constant and might be worse at night. The pain often increases with activity and might result in a limp if the tumor is in a leg bone.

Swelling in the area is another common symptom, although it might not occur until later. Depending on where the tumor is, it might be possible to feel a lump or mass.

Limb pain and swelling are very common in normal, active children and teens. They are much more likely to be caused by normal bumps and bruises, so they might not prompt a doctor visit right away. This can delay a diagnosis. If your child has these symptoms and they don't go away within a few weeks (or they get worse), see a doctor so that the cause can be found and treated, if needed.

These symptoms are less common in adults, so they should be a sign to see a doctor even sooner.

Bone fractures (breaks)

Although osteosarcoma might weaken the bone it develops in, fractures (breaks) are not common. Exceptions are rare telangiectatic osteosarcomas, which tend to weaken bones more than other forms of osteosarcoma and are more likely to cause breaks at the tumor site.

People with a fracture next to or through an osteosarcoma often describe a limb that was sore for a few months and suddenly became very painful when the fracture occurred.

Osteosarcoma is not a common cancer. Each year, about 800 to 900 new cases of osteosarcoma are diagnosed in the United States. About half of these are in children and teens.

Most osteosarcomas occur in children and young adults between the ages of 10 and 30. Teens are the most commonly affected age group, but people of any age can develop osteosarcoma. About 10% of all osteosarcomas occur in people older than 60.

About 2% of childhood cancers are osteosarcomas, but they make up a much smaller percentage of adult cancers.

The prognosis (outlook) for people with osteosarcoma depends on many factors, including the location of the tumor, whether the cancer has spread (metastasized) when it’s first found, and the person’s age. Statistics related to survival are discussed in Survival Rates for Osteosarcoma.

Visit the American Cancer Society’s Cancer Statistics Center for more key statistics.

A risk factor is anything that affects your chance of getting a disease such as cancer. Different cancers have different risk factors.

Lifestyle-related risk factors such as body weight, physical activity, diet, and tobacco use play a major role in many adult cancers. But these factors usually take many years to influence cancer risk, and they are not thought to play much of a role in childhood cancers, including childhood osteosarcomas. So far, lifestyle-related factors have not been linked to osteosarcomas in adults, either. Still, there are some factors that affect osteosarcoma risk.

Age

The risk of osteosarcoma is highest for those between the ages of 10 and 30, especially during the teenage growth spurt. This suggests there may be a link between rapid bone growth and risk of tumor formation. The risk goes down in middle age, but rises again in older adults (usually over the age of 60). Osteosarcoma in older adults is often linked to another cause, such as a long-standing bone disease.

Height

Children with osteosarcoma are usually tall for their age. This also suggests that osteosarcoma may be related to rapid bone growth.

Gender

Osteosarcoma is more common in males than in females. Females tend to develop it slightly earlier, possibly because they tend to have their growth spurts earlier.

Race/ethnicity

Osteosarcoma is slightly more common in African Americans and Hispanic/Latinos than in whites.

Radiation to bones

People who were treated with radiation therapy for another cancer might have a higher risk of later developing osteosarcoma in the area that was treated. Being treated at a younger age and being treated with higher doses of radiation both increase this risk.

It's not clear if imaging tests that use radiation, such as x-rays, CT scans, and bone scans, raise the risk of developing osteosarcoma. The amount of radiation used for these tests is many times lower than that used for radiation therapy. If there is any increased risk it is likely to be very small, but doctors try to limit the use of these types of tests whenever possible, especially in children, just in case.

Certain bone diseases

People with certain non-cancerous bone diseases have an increased risk of developing osteosarcoma.

Paget disease of the bone: In this condition, abnormal bone tissue forms in one or more bones. It mostly affects people older than 50. The affected bones are heavy and thick but are weaker than normal bones and are more likely to break. Usually this condition by itself is not life-threatening. But bone sarcomas (mostly osteosarcoma) develop in about 1% of people with Paget disease, usually when many bones are affected.

Hereditary multiple osteochondromas: Osteochondromas are benign bone tumors formed by bone and cartilage. Each osteochondroma has a very small risk of developing into a bone sarcoma (most often a chondrosarcoma, but less often it can be an osteosarcoma).

Most osteochondromas can be cured by surgery. However, some people inherit a tendency to develop many osteochondromas starting when they are young, and it may not be possible to remove them all. The more osteochondromas a person has, the greater the risk of developing a bone sarcoma.

Inherited cancer syndromes

People with certain rare, inherited cancer syndromes have an increased risk of developing osteosarcoma.

• Retinoblastoma is a rare eye cancer of children. Some children have the inherited form of retinoblastoma (hereditary retinoblastoma), in which all the cells of the body have a mutation (change) in the RB1 gene. These children also have an increased risk of developing bone or soft tissue sarcomas, including osteosarcoma. If radiation therapy is used to treat retinoblastoma, the risk of osteosarcoma in the bones around the eye is even higher.
• The Li-Fraumeni syndrome makes people much more likely to develop certain types of cancer, including breast cancer, brain tumors, osteosarcoma, and other types of sarcoma. This syndrome is usually caused by a mutation of the TP53 gene.
• Children with Rothmund-Thomson syndrome are short and tend to have skin and skeletal problems . They also are more likely to develop osteosarcoma. This syndrome is usually caused by abnormal changes in the REQL4 gene.
• Other rare inherited conditions, including Bloom syndrome, Werner syndrome, and Diamond-Blackfan anemia, have also been linked to an increased risk of osteosarcoma.

The way in which inherited gene changes make some people more likely to develop osteosarcoma is discussed in What Causes Osteosarcoma?

Researchers have found that osteosarcoma is linked with a number of other conditions, which are described in Osteosarcoma Risk Factors. But the cause of most osteosarcomas is not clear at this time.

Scientists have learned how certain changes in the DNA in bone cells can cause them to become cancerous. DNA is the chemical in each of our cells that makes up our genes, which control how our cells function. We usually look like our parents because they are the source of our DNA. But DNA affects more than how we look. It influences our risks for developing certain diseases, including some kinds of cancer.

Some genes (parts of our DNA) control when our cells grow, divide to make new cells, and die:

• Genes that help cells grow, divide, or stay alive are called oncogenes.
• Genes that slow down cell division or make cells die at the right time are called tumor suppressor genes.

Cancers can be caused by gene changes that turn on oncogenes or turn off tumor suppressor genes.

Some people inherit gene mutations (changes) from a parent that increase their risk of cancer. In this situation, all of the cells in the body carry the same gene change. These are called germline or inherited mutations. But more often, cancer-causing changes are acquired during life rather than inherited before birth. In this case, the change occurs only in the cells that will develop into cancer. These are called somatic or acquired gene changes.

Inherited gene changes

Some inherited DNA mutations cause syndromes that are linked with an increased risk of osteosarcoma. For example:

• The Li-Fraumeni syndrome is usually caused by inherited mutations that turn off the TP53 tumor suppressor gene. These mutations give a person a very high risk of developing one or more types of cancer, including breast cancer, brain tumors, osteosarcoma, and other cancers.
• Inherited changes in the retinoblastoma (RB1) tumor suppressor gene increase the risk of developing retinoblastoma, a type of eye cancer that affects children. Children with this gene change also have an increased risk for developing osteosarcoma, especially if they are treated with radiation.

If you are concerned you or your child might possibly have an inherited gene change, talk with your doctor about whether genetic testing might be helpful. You can also read more about this in Genetics and Cancer.

Acquired gene changes

Most osteosarcomas are not caused by inherited gene mutations, but instead are the result of gene changes acquired during the person’s lifetime.

Sometimes these gene changes are caused by radiation therapy used to treat another form of cancer, because radiation therapy can damage the DNA inside cells.

But many gene changes are probably just random events that sometimes happen inside a cell, without having an outside cause. Cells that are dividing quickly are more likely to create new cells with mistakes in their DNA, which increases the risk that a cancer such as osteosarcoma may develop. This may be why some normal situations (such as the teenage growth spurt) and some diseases (such as Paget disease of bone) that cause rapid bone growth increase the risk of osteosarcoma.

Other than radiation, there are no known lifestyle-related or environmental causes of osteosarcoma, so it's important to remember that in most cases there is nothing people with these cancers could have done to prevent them.

Researchers now understand some of the gene changes that occur in osteosarcomas, but it’s not always clear what causes these changes. As we learn more about what causes osteosarcoma, hopefully we will be able to use this knowledge to develop ways to better prevent and treat it.

At this time, there are no widely recommended screening tests for this cancer. (Screening is testing for cancer in people without any symptoms.)

Still, most osteosarcomas are found at an early stage, before they have clearly spread to other parts of the body. Symptoms such as bone pain or swelling often prompt a visit to a doctor. (For more on this, see Signs and Symptoms of Osteosarcoma.)

Some people who are at increased risk for osteosarcoma because of certain bone diseases or inherited conditions (listed in Osteosarcoma Risk Factors) might need increased monitoring for this disease. This type of cancer usually does not run in families, but looking out for the early signs is important if it is to be treated successfully.

It’s important to have honest, open discussions with your cancer care team. Ask any question, no matter how minor it might seem. For instance, consider these questions:

Before getting a bone biopsy

• How much experience do you have doing this type of biopsy? 
• Are you part of a team that treats bone cancers?
• What will happen during the biopsy?
• How long will it take to get the results from the biopsy?

If osteosarcoma has been diagnosed

• What kind of osteosarcoma do I (does my child) have? Will this affect treatment?
• Has the cancer spread beyond the bone it started in?
• What is the stage of the cancer and what does that mean?
• Do you think the cancer can be resected (removed) completely?
• Do we need any other tests before we can decide on treatment?
• How much experience do you have treating this type of cancer?
• Who else will be part of the treatment team, and what do they do?

When deciding on a treatment plan

• What are our treatment options?
• What do you recommend and why?
• Are there any clinical trials we should consider? How can we find out more about them?
• What’s the goal of treatment?
• Should we get a second opinion? How do we do that? Can you recommend someone?
• How soon do we need to start treatment?
• How long will treatment last? What will it be like? Where will it be done?
• How will treatment affect our daily lives?
• What should I (we) do to be ready for treatment?
• What are the possible risks and side effects of the suggested treatments?
• Which side effects start shortly after treatment and which ones might develop later on?
• Will treatment affect my child’s ability to grow and develop?
• Are there fertility issues we need to consider?

During and after treatment

• How will we know if the treatment is working?
• Is there anything we can do to help manage side effects?
• What symptoms or side effects should we tell you about right away?
• How can we reach you or someone on your team on nights, holidays, or weekends?
• Who can we talk to if we have questions about costs, insurance coverage, or social support? 
• What are the chances of the cancer coming back with these treatment plans? What might our options be if this happens?
• What type of follow up and rehab will be needed after treatment?
• Are there nearby support groups or other families who have been through this that we could talk to?

Along with these sample questions, be sure to write down some of your own. For instance, you might want more information about recovery times so you can plan work or school schedules.

Keep in mind that doctors aren’t the only ones who can give you information. Other health care professionals, such as nurses and social workers, can answer some of your questions. To find more about speaking with your health care team, see The Doctor-Patient Relationship.

During treatment for osteosarcoma, the main concerns for most people the daily aspects of just getting through treatment and beating the cancer. After treatment, the concerns tend to shift toward the short- and long-term effects of the cancer and its treatment, and the cancer coming back. 

It’s certainly normal to want to put the tumor and its treatment behind you and to get back to a life that doesn’t revolve around cancer. But it’s important to realize that follow-up care is a central part of this process that offers the best chance for recovery and long-term survival.

Follow-up care

After treatment is over, it’s very important to go to all follow-up appointments. During these visits, doctors will ask about symptoms and do physical exams, and might order blood tests or imaging tests such as MRI, CT scans or x-rays. Follow-up visits are needed to check for cancer recurrence or spread, as well as possible side effects of treatment. This is a good time for you to ask the health care team any questions and to discuss any concerns you might have.

You or your child will probably see the oncologist and the orthopedic surgeon and get imaging tests every few months during the first couple of years after treatment, and less often after that if there are no issues.

Physical therapy and rehabilitation are typically a very important part of recovery after treatment for osteosarcoma, and your doctors and other health providers will continue to monitor your (child’s) progress as time goes on.

Some chemotherapy drugs can cause problems with hearing or heart damage. People who get these drugs may also have tests to check hearing or heart function.

Almost any cancer treatment can have side effects. Some may last for only a short time, but others can last longer or might not show up until months or even years later. For example, in younger people, treatment might affect fertility (the ability to have children) later in life. It's important to talk to the cancer care team to learn about what to look for, and to tell them about any symptoms or side effects so they can help manage them.

Ask the cancer care team for a survivorship care plan

Talk with the treatment team about developing a survivorship care plan. This plan might include: 

• A suggested schedule for follow-up exams and tests
• A schedule for other tests that might be needed in the future, such as early detection (screening) tests for other types of cancer, or tests to look for long-term health effects from the cancer or its treatment
• A list of possible late- or long-term side effects from treatment, including what to watch for and when to contact the doctor

Keeping health insurance and copies of medical records

As much as you may want to put the experience behind you once treatment is completed, it’s also very important to keep good records of your (child’s) medical care during this time. Gathering these details soon after treatment may be easier than trying to get them at some point in the future. This can be very helpful later on if you (or your child) change doctors. Learn more about this in Keeping Copies of Important Medical Records.

It’s also very important to keep health insurance coverage. Tests and doctor visits can cost a lot, and even though no one wants to think of the tumor coming back, this could happen.

Late and long-term effects of treatment

Osteosarcoma treatment might affect a person’s health later in life. Young people in particular are at risk for possible late effects of their treatment. This risk depends on many factors, such as the specific treatments they received, doses of treatment, and their age when treated.

For example, the after-effects of surgery can range from small scars to the loss of a limb, which would require both physical rehabilitation and emotional adjustment.

Other late effects of treatment can include:

• Heart or lung problems (due to certain chemo drugs or radiation therapy to the chest)
• Loss of hearing (due to certain chemo drugs)
• Slowed growth and development (in the bones or overall)
• Changes in sexual development and ability to have children
• Learning problems in younger children
• Development of second cancers

Other possible complications might come up as well. Your child’s doctor should carefully review any possible problems with you before your child starts treatment. For more information, see Late Effects of Childhood Cancer Treatment.

To help increase awareness of late effects and improve follow-up care of childhood cancer survivors throughout their lives, the Children’s Oncology Group (COG) has developed long-term follow-up guidelines for survivors of childhood cancers. These guidelines can help you know what to watch for, what types of screening tests should be done to look for problems, and how late effects are treated.

It’s very important to discuss possible long-term complications with your child’s health care team, and to make sure there is a plan in place to watch for these problems and treat them, if needed. To learn more, ask your child’s doctors about the COG survivor guidelines. You can also download them for free at the COG website: www.survivorshipguidelines.org. The guidelines are written for health care professionals. Patient versions of some of the guidelines are available (as “Health Links”) on the site as well, but we urge you to discuss them with a doctor.

Social and emotional issues

Most osteosarcomas develop during the teenage or young adult years, a very sensitive time in a person’s life. Osteosarcoma and its treatment can have a profound effect on how a person looks and how they view themselves and their body. It can also affect how they do some everyday tasks, including certain school, work, or recreational activities. These effects are often greatest during the first year of treatment, but they can be long-lasting in some people. It’s important that the treating center assess the family situation as soon as possible, so that any areas of concern can be addressed.

These types of issues can often be addressed with support and encouragement. Doctors and other members of the health care team can also often recommend special support programs and services to help children after cancer treatment. For more information, see When Your Child's Treatment Ends.

No one chooses to have osteosarcoma, but for many people, the experience can eventually be positive, helping to establish strong self-values. Other people may have a harder time recovering, adjusting to life after cancer, and moving on. It is normal to have some anxiety or other emotional reactions after treatment, but feeling overly worried, depressed, or angry can affect many parts of a young person’s growth. It can get in the way of relationships, school, work, and other aspects of life.

With support from family, friends, other survivors, mental health professionals, and others, many people who have survived cancer can thrive in spite of the challenges they’ve had to face. If needed, doctors and other members of the health care team can often recommend special support programs and services to help after cancer treatment.

Although osteosarcoma and its treatment can have social and emotional effects on children and teens (and their families), adults with this disease face many of the same challenges, and are also encouraged to take advantage of the cancer center’s physical therapy, occupational therapy, and counseling services.