Bone Sarcoma

Bone sarcoma is a rare type of cancer that starts in the bones themselves, affecting fewer than 1% of all cancer diagnoses, yet carrying significant challenges for those who face it.

Table of contents

• What is bone sarcoma?
• Types of bone sarcoma
• Symptoms
• Causes and risk factors
• Getting diagnosed
• Treatment
• Survival and outlook
• Living with bone sarcoma

What is bone sarcoma?

Bone sarcoma, also called primary bone cancer, is a cancer that starts in the cells of the bones^[1]. This is different from secondary bone cancer, which spreads to the bones from another part of the body^[1]. When cancer from an organ like the lung, breast, or kidney travels to the bone, it is still named for where it began, not as bone cancer^[2].

The human skeleton is made up of more than 200 bones that support the body, protect internal organs, and work with muscles to allow movement^[1]. Bone sarcoma is rare, making up less than 1% of all cancer diagnoses in adults and about 15% of childhood cancer diagnoses^[4]. In the United States, approximately 1,000 to 1,200 people are diagnosed with bone sarcoma each year^[8][16].

Bone sarcoma can start in any bone in the body, but most commonly affects the long bones of the arms and legs^[2]. About 40% of bone sarcomas occur in the lower body parts like legs, ankles, and feet, while 15% occur in the upper body parts like shoulders, arms, wrists, and hands^[4]. The areas most often affected include the ends of long bones, particularly near the knee, hip, and shoulder joints^[3][12].

Types of bone sarcoma

There are several different types of bone sarcoma. The most common forms are osteosarcoma, chondrosarcoma, and Ewing sarcoma^[3]. Each type develops from different cells within the bone and affects people at different ages.

Osteosarcoma is the most common bone cancer, accounting for nearly two-thirds of all cases^[16]. It develops from cells that form new bone tissue and most often occurs in children and teenagers^[3]. The cancer typically develops in the metaphysis of long bones, which is the area where bone growth and elongation happen^[16]. Nearly 60% of osteosarcomas occur in the lower end of the thighbone, upper end of the shinbone, and upper end of the upper arm bone^[16].

Chondrosarcoma starts in the cartilage, which is the flexible connective tissue that lines the joints between bones^[3]. This type of bone sarcoma is more common in adults, particularly those older than 40 years^[5]. Chondrosarcoma is often found in the pelvis, upper leg, and shoulder bones^[3].

Ewing sarcoma is the second most common bone cancer, comprising about one-third of cases^[16]. It can occur in any bone and also in soft tissue^[3]. Although most common in children and adolescents, it does occur in adults^[3]. The areas most commonly affected include the pelvis, thighbone, lower leg, upper arm, and chest wall^[3].

Less common types of bone sarcoma include chordoma, which most commonly affects adults around 40 to 60 years old and is usually found in the bottom of the spine^[6]. Giant cell tumor of the bone is usually a non-cancerous tumor that grows in the bone, though it can become cancerous in rare cases^[3][6].

Symptoms

Pain, swelling, and problems moving around are the most common symptoms of bone sarcoma^[1]. However, the symptoms can vary depending on the size of the cancer and where it is in the body^[1].

The most common signs of bone sarcoma include bone pain that gradually becomes more persistent, usually worse at night and may feel throbbing, aching, or stabbing^[22]. There may be a lump in the affected area that can be hard or soft to the touch^[22]. Unexplained swelling around the affected area of the bone is another common symptom^[22].

Some people experience difficulty moving around, especially if swelling is near a joint^[22]. A weakened bone can lead to broken bones that happen suddenly or from injuries that normally wouldn’t cause breaks^[2][12]. Other symptoms may include feeling very tired, fever, and losing weight without trying^[2][22].

The symptoms of bone sarcoma can be challenging to identify because they are similar to common musculoskeletal injuries^[16]. Bony pain that manifests after minor injury, persists, causes nighttime awakening, or is associated with swelling should be evaluated^[16]. Some bone sarcomas can be painless, depending on where they develop and how fast they grow^[12].

Causes and risk factors

Experts aren’t certain what causes bone sarcoma^[22]. Bone sarcomas form when problems with cell DNA cause cells to grow out of control^[22]. The cancer is thought to originate from cells within the bone that develop changes to their DNA and grow in an unregulated way^[4].

Certain factors may raise the risk of developing bone sarcoma. Rapid bone growth during growth spurts increases the risk, which is why bone sarcoma is most common in children and teenagers whose bodies are developing rapidly^[12]. Osteosarcoma tends to occur at the age and location where bone growth is most active^[16].

Past treatment with chemotherapy or radiation for another type of cancer can increase the risk of developing bone sarcoma^[10][12]. Exposure to high doses of radiation from previous cancer treatment or from other sources may cause bone sarcoma^[12].

Certain genetic conditions increase the risk. A genetic change that affects the p53 gene may cause some kinds of cancers, including bone sarcoma^[12]. The p53 gene is sometimes known as a tumor suppressor gene because it helps the body stop tumors from forming^[12]. Bone sarcoma may also be related to the retinoblastoma gene, which can be associated with eye cancers in young children^[12].

Risk factors also include certain inherited conditions such as Li-Fraumeni syndrome, Bloom syndrome, Diamond-Blackfan anemia, Paget disease, hereditary retinoblastoma, Rothmund-Thomson syndrome, and Werner syndrome^[10]. Rare disorders of the bones such as Ollier’s disease and Maffucci syndrome are risk factors for chondrosarcoma^[3].

Getting diagnosed

You usually start by seeing your general practitioner. They will examine you and might refer you for tests or to see a specialist^[1]. If bone sarcoma is suspected, timely diagnosis is important, though it can be challenging because symptoms are often similar to common musculoskeletal injuries^[16].

Plain radiography, or X-rays, is the preferred first diagnostic test^[16][23]. Imaging tests make pictures of the body and can show the location and size of a bone sarcoma^[2]. Additional imaging tests might include magnetic resonance imaging (MRI), computed tomography scan (CT), bone scan, and positron emission tomography scan (PET scan)^[2][23].

To be certain whether a growth in the bones is cancer, a piece of tissue is removed and tested for cancer cells through a procedure called a biopsy^[2]. The tissue might be removed using a needle that is put through the skin and into the cancer, or sometimes surgery is needed to get the tissue sample^[2]. The sample is tested in a laboratory to see if it is cancer, and other special tests give more details about the cancer cells^[2].

Determining the type of biopsy needed and how it should be done requires careful planning by the medical team^[2]. The biopsy needs to be done so that it won’t get in the way of future surgery to remove the cancer^[2]. Patients with suspected bone cancer should be referred immediately to a cancer center experienced with bone tumors, and the biopsy should be performed by an experienced surgeon^[16].

After bone sarcoma has been diagnosed, imaging tests are done to find out if cancer cells have spread within the bone or to other parts of the body^[10]. The next step is to assess the size of the tumor and how it is affecting surrounding normal body tissues such as muscles, arteries, and nerves^[19]. Tests also check if the tumor has spread to any other part of the body such as the lungs or another bone, which is done with lung CT scan and either bone scan or PET scan^[19].

Treatment

The main treatments for bone sarcoma include surgery, chemotherapy, and radiotherapy^[1][14]. The treatment you have will depend on the type of bone sarcoma, where the cancer is, how far it has grown or spread, your age, your general health, and your treatment preferences^[14].

Surgery is one of the main treatments for bone sarcoma^[14][15]. The goal of surgery is to remove all the cancer cells^[2]. The type of surgery you need depends on things such as the size of the cancer, where the tumor is, and whether it has spread to other areas of your body^[17].

Types of surgery include wide resection, which removes the bone tumor and a small amount of bone and tissue around it^[15]. Limb-sparing surgery removes the bone containing cancer and replaces it with a metal implant or bone from another part of your body^[1][15]. This approach is often used to remove tumors in an arm or leg, and about 90% to 95% of patients do not require limb amputation^[16]. Amputation, removing all or part of the affected limb, may be needed in some cases if the cancer has grown into the nerves or blood vessels or if the tumor is very big^[3][15].

Chemotherapy uses medicines to kill cancer cells^[14]. It works well for some types of bone sarcomas such as Ewing sarcoma and osteosarcoma^[14]. You usually have chemotherapy before and after surgery^[14]. Before surgery, chemotherapy treatment can shrink the cancer and make it easier to remove^[14]. After surgery, chemotherapy can kill off any cancer cells that may have escaped before the operation, lowering the risk of the cancer coming back^[14].

For young adults, the standard chemotherapy drug combination used for osteosarcoma includes high-dose methotrexate, doxorubicin, and cisplatin^[15]. The use of chemotherapy in combination with surgery has improved survival rates to nearly 80% for patients with localized disease^[16].

Radiotherapy uses high-energy waves similar to X-rays to kill cancer cells^[14]. It is not a standard treatment for all types of bone sarcoma, but it can be an important part of treatment for some bone cancers such as Ewing sarcoma^[14]. For Ewing sarcoma, you can have radiotherapy before or after surgery, depending on where the cancer is^[14].

Some people with bone sarcoma may have targeted cancer drugs, which aim to stop the cancer growing^[14][17]. They may be recommended depending on the type of bone sarcoma you have, how big the cancer is, and your general level of health^[14].

An expert team of doctors and other professionals who specialize in bone sarcoma will discuss the best treatment and care for you^[14]. They are called a multidisciplinary team and are based at specialist sarcoma centers^[14]. The team includes specialist bone cancer surgeons, cancer doctors who treat cancer with drugs, cancer doctors who treat with radiotherapy, pathologists, radiologists, specialist cancer nurses, physiotherapists, occupational therapists, and others^[14].

Survival and outlook

Survival depends on many factors including the stage and type of your cancer^[1]. The most important factor affecting outlook is whether the cancer has spread to other parts of the body^[16].

For osteosarcoma, when the disease is localized and has not spread, the five-year survival rate is nearly 80%^[16]. However, the presence of metastasis, when cancer spreads to other parts of the body, lowers the five-year survival rate to 20% to 30%^[16]. The most common site for osteosarcoma to spread is the lungs^[16].

Ewing sarcoma has a similar prognosis to osteosarcoma, with survival depending heavily on whether the cancer has spread^[16]. Chondrosarcoma generally has higher survival rates because most of these tumors are low-grade lesions, meaning they grow more slowly^[5].

Around 7 in 10 people with osteosarcoma survive if the cancer doesn’t spread to other parts of their bodies^[12]. The survival rate for bone sarcoma has improved significantly over the past several decades due to advances in treatment, particularly the use of chemotherapy combined with surgery^[16].

Living with bone sarcoma

After completion of treatment, people go on a schedule to undergo several imaging scans per year to check if the tumor is coming back^[19]. This is called “surveillance” and lasts approximately five years^[19]. You’ll have regular check-ups during and after any treatments^[1].

With respect to physical function after surgery, people can expect a good quality of life, however virtually all patients do experience some degree of limitation^[19]. Most people should plan for many months if not over a year of gradual recovery that includes physical therapy^[19]. As part of recovery, you will need physiotherapy to help you regain your mobility^[17].

Getting practical and emotional support can help you cope with a diagnosis of bone sarcoma^[1]. Coping with a diagnosis of bone cancer can be overwhelming, and help and support are available^[21]. You might have a number of different feelings when you’re told you have cancer, such as feeling shocked, upset, frightened, confused, angry, guilty, or sad^[21]. Everyone reacts in their own way, and there is no set way of handling the news^[21].

Taking in information can be difficult, especially when you have just been diagnosed^[21]. Make a list of questions before you see your doctor, and take someone with you to remind you what you want to ask and help you remember the information that was given^[21]. Remember that you don’t have to sort everything out at once^[21].

Talking to your friends and relatives about your cancer can help and support you^[21]. Help your family and friends by letting them know if you would like to talk about what’s happening and how you feel^[21]. If your bone sarcoma has spread or cannot be cured, you’ll be referred to a special team of doctors and nurses called the palliative care team or symptom control team who will work with you to help manage your symptoms and make you feel more comfortable^[17].

primary bone cancer, bone cancer