Bone sarcoma is a rare type of cancer that starts in the bones themselves, affecting fewer than 1% of all cancer diagnoses. While the word “cancer” naturally brings worry and uncertainty, understanding what bone sarcoma is, how it develops, and what can be done about it can help patients and families navigate this challenging journey with more confidence and clarity.

Understanding Bone Sarcoma

Bone sarcoma, also called primary bone cancer, is a disease where cancer cells begin growing in the bone tissue itself. This is different from cancer that starts somewhere else in the body and then spreads to the bones, which doctors call secondary or metastatic bone cancer. When cancer originates in the bone, it develops from the cells that normally build and maintain healthy bone structure.^[1]

The human skeleton contains more than 200 bones that work together to support the body, protect vital organs, and allow movement by acting as levers for muscles. When bone sarcoma develops, cancerous cells create abnormal bone tissue that can damage the healthy bone structure around it. Without treatment, these cancer cells can spread to other parts of the body, most commonly to the lungs.^[1][2]

There are several different types of bone sarcoma, and each type has its own characteristics and patterns. The three most common forms are osteosarcoma, which develops in cells that form new bone tissue; Ewing sarcoma, which can occur in bone or surrounding soft tissue; and chondrosarcoma, which starts in the cartilage that lines joints between bones. Each type behaves differently and may require slightly different treatment approaches.^[3][6]

How Common Is Bone Sarcoma?

Bone sarcoma is quite rare compared to other types of cancer. In the United States, approximately 16,000 sarcomas are diagnosed each year, with around 4,000 of these being bone sarcomas specifically. This means bone sarcomas make up only about 1% of all adult cancer diagnoses. However, they represent a much larger portion of childhood cancers, accounting for roughly 15% of cancer diagnoses in children.^[4]

In the United Kingdom, bone sarcoma makes up only 0.2% of all cancer diagnoses in England, with an average of 500 people diagnosed each year. The rarity of this disease means that many doctors may see very few cases throughout their careers, which is why referral to specialized cancer centers with experience treating bone sarcomas is so important.^[6]

Different types of bone sarcoma affect different age groups. Osteosarcoma, the most common type, primarily affects children, teenagers, and young adults, with diagnosis most often occurring around age 12 for girls and age 16 for boys. This timing coincides with periods of rapid bone growth during adolescence. There is also a smaller increase in osteosarcoma cases among people older than 60 years. Ewing sarcoma similarly affects mostly children and teenagers, with the highest incidence occurring in people aged 10 to 19 years. Chondrosarcoma, on the other hand, primarily affects adults older than 40 years.^[2][16]

What Causes Bone Sarcoma?

Scientists don’t fully understand what causes bone sarcoma to develop. Like other cancers, bone sarcoma forms when something goes wrong with the DNA inside bone cells, causing them to grow and divide in an uncontrolled way. Instead of following normal patterns of growth and death, these cells keep multiplying and eventually form a mass of tissue called a tumor.^[2]

One theory about osteosarcoma suggests it originates from malignant primitive cells that should normally develop into healthy bone-forming cells called osteoblasts. When these cells become cancerous, they produce an abnormal version of the bone tissue matrix. Because osteosarcomas tend to develop in the metaphysis, which is the part of a long bone that contains the growth plate responsible for bone elongation, researchers believe the cancer may be related to the active bone formation process that occurs during growth spurts.^[13][16]

For Ewing sarcoma, the cell of origin remains unknown. Some researchers hypothesize these tumors may derive from undifferentiated primitive cells or neural crest cells, while more recent suggestions point to primitive stem cells, with the degree of malignancy depending on when the stem cell development gets arrested.^[16]

Who Is at Risk?

While anyone can develop bone sarcoma, certain factors appear to increase a person’s risk. Age is one of the most significant factors. Teenagers and young adults face the highest risk for osteosarcoma and Ewing sarcoma because these cancers tend to develop during periods of rapid bone growth. The average age of osteosarcoma diagnosis is 15 years, reflecting the connection between bone growth spurts and cancer development.^[12]

Previous exposure to radiation can increase bone sarcoma risk. People who have received radiation therapy as treatment for another type of cancer may develop bone sarcoma later in life. Similarly, exposure to high doses of radiation at work or in the environment may raise the risk.^[4][12]

Certain genetic conditions and inherited disorders can make bone sarcoma more likely to develop. These include conditions such as retinoblastoma, which causes tumors in the eye, and Li-Fraumeni syndrome, which increases the risk of several types of cancer. Paget’s disease, a chronic condition that affects bone growth and typically occurs in older adults, can occasionally develop into osteosarcoma. People with rare bone disorders such as Ollier’s disease and Maffucci syndrome face increased risk for chondrosarcoma.^[3][10]

Some studies have found that bone sarcoma occurs more frequently in males than in females. Ewing sarcoma is more common in people who are white or Asian compared to those who are Black. For Ewing sarcoma, the estimated incidence is approximately one in 100,000 among people aged 10 to 19 years.^[4][16]

Past treatment with certain types of chemotherapy has also been associated with increased risk of developing bone sarcoma. Additionally, a condition called bone infarction, which happens when blood supply to bone tissue is cut off, may lead to the formation of cancerous cells as healthy bone cells die from lack of blood.^[12]

Recognizing the Symptoms

The symptoms of bone sarcoma can be confusing because they often resemble common injuries or growing pains, especially in children and teenagers. This similarity to everyday aches and pains can delay diagnosis, as both patients and doctors may initially think the symptoms are from sports injuries, arthritis, or normal growth-related discomfort.^[16]

The most common symptom of bone sarcoma is bone pain. This pain typically develops gradually and becomes more persistent over time. Unlike pain from an injury that improves with rest, bone cancer pain often gets worse at night and may wake a person from sleep. The pain may feel throbbing, aching, or stabbing. As the cancer grows, the pain may become more intense and constant.^[2][22]

Swelling and tenderness near the affected area are also common signs of bone sarcoma. A lump or mass may develop that can be felt through the skin. The area around the tumor might feel warm to the touch. As swelling increases, it can cause problems with movement, especially if the tumor is located near a joint such as the knee, hip, or shoulder.^[2][3]

Sometimes bone sarcoma weakens the bone so much that it breaks from minor trauma or even without any injury at all. Doctors call this a pathologic fracture. A bone that breaks unexpectedly or from an injury that normally wouldn’t cause a break should always be evaluated for possible bone cancer.^[2][12]

Other symptoms may include difficulty moving around, particularly if the tumor affects a leg bone, which can cause limping. Some people with bone sarcoma experience extreme tiredness that doesn’t improve with rest. Unexplained weight loss and fever can also occur, though these are less common symptoms.^[2][4]

The specific symptoms someone experiences depend on several factors, including where the tumor is located in the body and how large it has grown. For example, if the tumor is in an arm bone, lifting objects may be painful. If it’s in a leg bone, walking may become difficult. Tumors in less common locations, such as the pelvis, jaw, or spine, may cause symptoms specific to those areas.^[2]

How Bone Sarcoma Is Diagnosed

When a doctor suspects bone sarcoma based on symptoms and physical examination, several tests are typically performed to confirm the diagnosis and understand more about the tumor. The diagnostic process usually begins with imaging tests that create pictures of the bone and surrounding tissues.^[23]

An X-ray is usually the first imaging test ordered because it can show abnormal areas in the bone. X-rays are relatively quick, inexpensive, and can provide important initial information about whether a bone tumor might be present. If an X-ray raises suspicion of bone cancer, additional imaging tests are typically needed.^[16]

Magnetic resonance imaging, or MRI, uses powerful magnets and radio waves to create detailed images of bones and soft tissues. MRI scans are particularly useful for showing the exact size of the tumor and whether it has spread into surrounding muscles, blood vessels, or nerves. This information helps doctors plan surgery and other treatments.^[23]

A computed tomography scan, or CT scan, creates cross-sectional images of the body using X-rays taken from multiple angles. CT scans are especially helpful for checking whether bone cancer has spread to the lungs, which is the most common site of metastasis for bone sarcomas. Doctors also use CT scans to get detailed views of complex bone structures.^[23]

A bone scan involves injecting a small amount of radioactive material into a vein. This material travels through the bloodstream and collects in areas where bone is growing or repairing itself, including cancer sites. A bone scan can show whether cancer has spread to other bones in the body.^[23]

A positron emission tomography scan, or PET scan, uses a different type of radioactive tracer that collects in rapidly growing cells, including cancer cells. PET scans can help identify areas of cancer throughout the body and are sometimes combined with CT scans for more detailed information.^[23]

While imaging tests can suggest that a tumor might be cancer, the only way to know for certain is through a biopsy. During a biopsy, a doctor removes a small sample of tissue from the tumor, which is then examined under a microscope by a specialist called a pathologist. The pathologist looks for cancer cells and determines what type of bone sarcoma it is.^[1][23]

There are two main types of biopsies for bone tumors. In a needle biopsy, a thin needle is inserted through the skin and guided into the tumor to collect tissue samples. In a surgical biopsy, a surgeon makes an incision in the skin to access the tumor and removes a piece of it for testing. The type of biopsy performed depends on the tumor’s location and size.^[23]

Where Bone Sarcoma Develops

Bone sarcoma can develop in any bone in the body, but certain bones are affected more commonly than others. About 40% of bone sarcomas occur in the lower extremities, meaning the legs, ankles, and feet. Another 15% develop in the upper extremities, including the shoulders, arms, wrists, and hands. Approximately 30% form in the trunk, chest wall, abdomen, or pelvis, and about 15% occur in the head and neck region.^[4]

Osteosarcoma typically develops in the long bones of the arms and legs, particularly in the areas near the ends of these bones where they meet at joints. Nearly 60% of osteosarcomas occur in three specific locations: the distal femur (the lower part of the thigh bone near the knee), the proximal tibia (the upper part of the shin bone near the knee), and the proximal humerus (the upper part of the arm bone near the shoulder). Less commonly, osteosarcoma can develop in the pelvis, head, neck, or even in soft tissues or organs in the chest or abdomen.^[3][16]

Ewing sarcoma can affect any bone in the body and can also occur in soft tissue. The areas most commonly affected include the pelvis, thigh bone, lower leg, upper arm, and chest wall. Like osteosarcoma, Ewing sarcoma tends to affect the long bones but can develop in flat bones as well.^[3]

Chondrosarcoma is often found in the pelvis, upper leg, and shoulder bones. Because this type of bone sarcoma grows in cartilage, it tends to occur in areas where cartilage is present between joints. Another rare type called chordoma most commonly affects the bottom of the spine, known as the sacrum, or the base of the skull.^[3][6]

How Bone Sarcoma Can Spread

One of the most concerning aspects of bone sarcoma is its ability to spread to other parts of the body through a process called metastasis. Understanding how bone sarcoma spreads helps explain why early diagnosis and comprehensive treatment are so important.^[2]

Bone sarcoma can spread in several ways. Sometimes cancer cells break away from the main tumor and travel through the bloodstream to distant organs. The lungs are by far the most common site where bone sarcoma spreads. In fact, checking the lungs for signs of spread is a routine part of the initial evaluation for anyone diagnosed with bone sarcoma. If cancer cells reach the lungs and begin growing there, they form lung metastases.^[16]

After the lungs, bones in other parts of the body are the second most common location for bone sarcoma to spread. For example, cancer that starts in a leg bone might later appear in an arm bone or another leg bone. Less commonly, bone sarcoma can spread to other organs.^[16]

In some cases, bone sarcoma can spread within the same bone where it started or to adjacent areas. Primary tumors can form what doctors call “skip lesions,” which are separate tumor deposits within the same bone. Sometimes cancer can spread across a joint from one bone to another, such as from the tibia to the femur across the knee joint.^[9]

The presence or absence of metastasis has a major impact on prognosis. When bone sarcoma is detected before it has spread, treatment outcomes are generally much better. This is why early recognition of symptoms and prompt referral to specialized cancer centers are so critical.^[4]

Treatment Approaches

The treatment of bone sarcoma typically involves a combination of therapies working together. Surgery, chemotherapy, and radiation therapy are the main treatment options, though not every patient will need all three. The specific treatment plan depends on the type of bone sarcoma, where it’s located, how large it is, whether it has spread, and the patient’s overall health.^[1][14]

Surgery is one of the most important treatments for bone sarcoma. The goal of surgery is to remove the entire tumor along with a margin of normal tissue around it to ensure no cancer cells are left behind. The type of surgery needed varies depending on the tumor’s size, location, and whether it has grown into surrounding tissues.^[14]

Many patients can have limb-sparing surgery, also called limb salvage surgery, where the surgeon removes the cancerous bone but saves the arm or leg. The removed bone is then replaced with a metal implant, called a prosthesis, or with bone taken from another part of the body or from a donor. This type of surgery has become more common over the years, and now 90% to 95% of patients with bone sarcoma in an arm or leg do not require amputation.^[9][11]

In some situations, amputation may be necessary. This might be recommended if the cancer has grown into nerves or blood vessels, if the tumor is very large, or if cancer comes back after limb-sparing surgery. While losing a limb is difficult, amputation may offer some patients a better chance of being cured and, in certain cases, a better quality of life than limb salvage surgery. Most people who have an amputation use an artificial limb after surgery.^[11][19]

Chemotherapy uses anti-cancer drugs to destroy cancer cells throughout the body. It’s a standard treatment for osteosarcoma and Ewing sarcoma. Chemotherapy is typically given both before and after surgery. When given before surgery, called neoadjuvant chemotherapy, it can shrink the tumor and make it easier to remove. After surgery, called adjuvant chemotherapy, it destroys any remaining cancer cells and reduces the risk of the cancer coming back.^[14][15]

For young adults with osteosarcoma, the standard chemotherapy combination includes high-dose methotrexate, doxorubicin, and cisplatin, often abbreviated as MAP. Other drug combinations may include ifosfamide, sometimes with etoposide, or carboplatin with ifosfamide and doxorubicin. Chemotherapy treatment typically lasts many months, with the full course often taking six to nine months or longer after surgery.^[15]

Radiation therapy uses high-energy rays similar to X-rays to kill cancer cells. It’s not always used for bone sarcoma, but it can be an important part of treatment for Ewing sarcoma. Radiation might be given before or after surgery, depending on where the cancer is located. If surgery isn’t possible or appropriate, radiation therapy may be used instead. For some bone cancers, such as osteosarcoma and chondrosarcoma, radiation therapy may be used to reduce the chance of cancer returning after surgery.^[14][17]

Some patients may receive targeted medicines or participate in clinical trials testing new treatments. Targeted medicines work by stopping specific processes that cancer cells need to grow. The availability of these treatments depends on the type and stage of bone sarcoma, as well as what other treatments have already been tried.^[14]

Living with and After Treatment

The journey with bone sarcoma extends well beyond the active treatment phase. Recovery from treatment takes time, and most people should plan for many months, if not over a year, of gradual recovery that includes physical therapy. The recovery process and long-term effects depend heavily on the specific details of each person’s tumor and surgery.^[19]

After completing treatment, patients enter a surveillance period where they undergo regular imaging scans to check whether the tumor is coming back. This monitoring typically continues for approximately five years and may include several scans per year. While this period can be emotionally challenging, regular surveillance allows doctors to catch any recurrence early when it’s most treatable.^[19][20]

Physical function after bone sarcoma surgery varies significantly from person to person based on the details of their tumor and treatment. While most people can expect a good quality of life, virtually all patients experience some degree of limitation. Physical therapy plays a crucial role in helping patients regain mobility and strength. The rehabilitation process often requires patience and persistence, as improvements may continue for months or even years after surgery.^[19]

The emotional impact of bone sarcoma extends beyond physical recovery. Patients may experience a range of powerful emotions including shock, fear, anger, sadness, and uncertainty. These feelings may come and go unpredictably, even long after treatment ends. Some people find it helpful to talk with friends and family about their experiences, while others prefer support groups where they can connect with people who have been through similar experiences.^[21]

For patients who have had an amputation, the loss of a limb can be particularly difficult to cope with. Some people experience emotions similar to grief and bereavement. Coming to terms with feelings about amputation may need as much attention as the practical adjustments to daily life. Learning to use a prosthetic limb takes time and practice, but most people eventually adapt well.^[21]

Practical matters also require attention during and after treatment. Medical appointments, treatment schedules, and recovery needs can significantly impact work, school, and family responsibilities. Financial concerns may arise from treatment costs, travel to specialized centers, time away from work, or the need for home modifications. Many cancer centers have social workers and financial counselors who can help patients navigate these challenges.^[18]