Osteosarcoma (osteogenic sarcoma) is a type of cancer that starts in your bones. In the beginning, the cancer cells appear to be regular bone cells. Then, they create tumors, and those tumors create immature, irregular, diseased bone. It is most often seen in teenagers, with the average age of diagnosis of osteosarcoma being 15.
A “sarcoma” is a type of cancer that develops in connective tissue such as bone, cartilage, or muscle. “Osteo” refers to bones.
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Osteosarcoma most often affects long bones, such as those in the arms and legs. It usually occurs near the ends of your bones (the metaphyses) and near your knee where the fastest growth is taking place (if you’re a teenager). The bones and areas most often affected include the:
- Femur (thigh bone) near your knee.
- Tibia (shin bone) near your knee.
- Humerus (upper arm bone) near your shoulder.
- Rarely, in the soft tissues or organs in your abdomen or chest.
Other less common locations for osteosarcoma include your:
- Pelvis.
- Skull.
- Jaw.
What is cancer?
There are trillions of cells in your body. Every day they grow, divide and form new cells. Cells die when they get old or damaged. Cancer happens when cells that should’ve died survive and new cells form when they’re not needed. This uncontrolled growth of cells eventually leads to enough extra cells that make masses. These masses are called “tumors.”
Osteosarcoma is one of many types of cancer.
What is a tumor?
A tumor is a lump or mass. Most cancers form tumors. Not all lumps are cancerous, so your healthcare provider will have to take a piece of the lump (by a biopsy) to determine if it is benign (not cancerous) or malignant (cancerous).
What are the types of osteosarcoma?
Osteosarcoma tumors can be categorized as low-grade, intermediate-grade, or high-grade. Low-grade means that your cancer will grow slowly and remain where it began (localized), while high-grade indicates that it will spread quickly and metastasize. (“Metastasize” is the process of cancer spreading to other parts of your body.)
Most osteosarcoma tumors found in children and teenagers are high-grade. The cells of high-grade osteosarcoma don’t look like normal bone under a microscope. There are nine types of high-grade osteosarcomas:
- Osteoblastic.
- Chondroblastic.
- Fibroblastic.
- Small cell.
- Telangiectatic.
- High-grade surface (juxtacortical high-grade).
- Pagetoid.
- Extraskeletal.
- Post-radiation.
There is one type of immediate-grade osteosarcoma:
- Periosteal (juxtacortical immediate grade.
And, there are two types of low-grade osteosarcomas:
- Parosteal (juxtacortial low grade).
- Intramedullary or intraosseous well-differentiated (low-grade central).
Who gets osteosarcoma? What are the risk factors?
Osteosarcoma most often affects pre-teens and teens; the average age at diagnosis is 15. More than 75% of the cases are people less than 25 years old. This may be related to the “growth spurt” most teens experience at that age. Osteosarcoma can also occur in children and young adults.
Osteosarcoma is slightly more common in African Americans. Before adolescence, it occurs equally in males and females. After adolescence, it occurs slightly more often in boys, possibly because of a longer period of skeletal growth.
You’re at a higher risk of osteosarcoma if you:
- Have gone through radiation treatment.
- Took alkylating agents, which are anticancer drugs.
- Have a certain change in your RB1 gene.
- Are a teenager.
- Have any of the following conditions: Bloom syndrome, Diamond-Blackfan anemia, Li-Fraumeni syndrome, Paget disease, Hereditary retinoblastoma, Rothmund-Thomson syndrome, or Werner syndrome.
How common is osteosarcoma?
Between 400 and 1,000 new cases of osteosarcoma are diagnosed in the United States each year.
Osteosarcoma accounts for about 3% of all childhood cancers. It is the most common primary bone tumor in children. Osteosarcoma is the third most common cancer in adolescence (after lymphomas and brain tumors).
Does osteosarcoma cause pain?
Osteosarcomas can cause pain. If there are tumors in the bones of your arm, for example, it may be painful to lift things. If the tumors are in the bones of your legs, it may cause limping. However, osteosarcomas can also be painless.
Why is osteosarcoma pain worse at night?
People have reported that, yes, osteosarcoma pain is worse during activity and at night. It is unclear why this happens.
Can I feel an osteosarcoma tumor?
Maybe. Sometimes the mass (tumor) can be felt through the skin, but other times they are either too small or too deep to be felt.
Is osteosarcoma deadly?
If the osteosarcoma doesn’t metastasize, survival rates are about 70%. If the cancer has spread to other parts of your body, your survival rate may be as low as 30% to 50%.
What causes osteosarcoma?
The direct cause of osteosarcoma is unknown. However, there are some risk factors, including:
- Rapid bone growth: The risk of osteosarcoma increases during a child and adolescent’s growth spurts.
- Exposure to radiation: This might have occurred from treatment for another type of cancer. This can take a few or several years to occur.
- Genetic factors: Osteosarcoma is one of several types of rare cancers in young people. This may be related to the retinoblastoma gene, which can be associated with eye cancers in young children or with other tumors in children and young adults in which a mutation of the p53 gene is involved.
- Bone infarction: This happens when there’s a lack of blood supply to your bone tissue. This destroys the cells.
What are the symptoms of osteosarcoma?
The most common symptoms of osteosarcoma include:
- Bone pain or tenderness.
- A mass or lump (tumor) that is warm and might be felt through your skin.
- Swelling and redness at the site of your tumor.
- Increased pain with lifting (if it affects your arm).
- Limping (if it affects your leg).
- Limited movement (if it affects a joint).
- Unexplained fever.
- Broken bone (sometimes this happens after a simple movement).
How is osteosarcoma diagnosed? What tests are done?
Your healthcare provider will begin with a thorough history and physical examination. They’ll ask about your symptoms and medical history; for example, any prior radiation treatment or whether anyone in your family has certain hereditary conditions. They’ll also look for lumps that may be protruding from bones.
Your healthcare provider might also use certain tests when making the diagnosis. These include:
- Blood tests: These tests can provide information about blood counts and how your organs (such as your kidneys and liver) are working. There is no blood test to detect the presence of a bone tumor.
- X-ray: An X-ray will be done to look for abnormal growths in your bones.
- Computed tomography (CT): CT uses computers to combine many X-ray images into cross-sectional views of the inside of your body. This test is used to look for any tumors in your lungs.
- Magnetic resonance imaging (MRI): MRI uses a large magnet, radio waves and a computer to create clear images of body parts. This may be ordered for more detailed pictures if an X-ray is not normal.
- Bone scan: This test uses a small amount of radioactive material injected into your body to identify bone disorders.
- ET scan: This test uses a special glucose tracer that shows the areas in your body where the glucose uptake is extra high. This tracer is often taken up in high concentrations in cancer cells.
- Biopsy: This is a procedure in which a piece of tissue from the affected area is removed so that it can be studied for cancer cells. The two most likely types of biopsy your healthcare provider will use are a core needle biopsy or a surgical biopsy.
After your healthcare provider diagnoses osteosarcoma, the next step is to find out if the cancer cells have spread of if they’ve remained localized. This is called “staging.” The cancer can spread through your blood, your lymph system, or tissues. If the cancer enters your lungs, it’s still referred to as osteosarcoma, not lung cancer. The following diagnostic tools may be used:
- X-ray: Organs such as other bones or your lungs will be X-rayed.
- Computed tomography: Another CT scan will also be performed. This is the best type of scan for evaluating your lungs.
- PET-CT: This test combines the images from the CT scan and a PET scan.
- MRI: Another MRI may be needed to get detailed pictures of other sites of cancer.
- Bone scan: A bone scan will see if the cancer cells have spread to other bones.
How is osteosarcoma treated? What are the options?
The most common forms of treatment for osteosarcoma are:
- Surgery: During surgery, the tumor and some of the healthy tissue around it will be cut out of the affected bone. In most cases involving the arm or leg, surgery can be done without amputation. This is called limb-salvage surgery. These procedures may be possible in those whose cancer has not spread beyond its original site. Sometimes, artificial implants or bone taken from another part of your body can be used to replace the bone that was removed during surgery. Unfortunately, there are some cases where a section or all of an arm or leg must be amputated. You’ll get a prosthesis (artificial limb) afterwards.
- Chemotherapy: This is the use of drugs to kill cancer cells. Chemotherapy is given before surgery to shrink the tumor and kill any cancer cells floating around in the blood, and after surgery to catch any cancer cells that might still be in your body. Chemotherapy before surgery is called “neoadjuvant chemotherapy” and typically takes about 10 weeks. Chemotherapy given after surgery to kill any remaining cancer cells is called “adjuvant chemotherapy.” The typical duration of adjuvant chemotherapy for osteosarcoma is an additional 18 weeks.
- Radiation therapy: Sometimes radiation is used to treat osteosarcoma. This is particularly important in areas where surgery is not possible. There are two types: external radiation therapy and internal radiation therapy. The external kind uses a machine that points radiation at the area of the body that is cancerous. Internal radiation therapy is where the substance is inserted via needle or catheter. For osteosarcoma, some patients are treated with bone-seeking radiopharmaceuticals (samarium or radium) that are taken up by the bone-forming osteosarcoma cancer cells, delivering radiation specifically to the cancer site.
- Targeted therapy: Targeted therapy is the use of drugs that block certain proteins that are important to cancer cells. These drugs typically don’t harm normal cells as much as chemotherapy or radiation. Kinase inhibitor therapy, mammalian target of rapamycin inhibitors and monoclonal antibody therapy are the most common drugs used.
- Cryosurgery: Liquid nitrogen is used to freeze and destroy cancer cells.
- Amputation: Amputation is the surgical removal of a limb. This is rare.
- Rotationplasty: This procedure is used on tumors of the distal femur, which is the area of the leg just above the knee. The leg is partially amputated, the tumor is removed and then the lower leg is rotated 180 degrees and reattached, using the ankle as a new knee. This converts the above-knee to a below-knee amputation that is more functional and helps fit a prosthesis. Your healthcare provider will discuss the cosmetic side effects if a rotationplasty is an option.
Who treats osteosarcoma?
It takes a team of healthcare providers to treat osteosarcoma. If your child has osteosarcoma, the team will be led by a pediatric oncologist (a physician who works with children who have cancer). They may add the following specialists to the team:
- Pediatric subspecialists (e.g. Pediatric cardiologist, Pediatric nephrologist etc.).
- Orthopedic surgeon.
- Radiation oncologist.
- Pediatric nurse specialist.
- Rehabilitation specialist.
- Child-life specialist.
- Social worker.
- Psychologist.
Are there any complications/side effects of treatment?
Yes. Side effects may stick around for months or even years. They might include:
- Problems with your heart, lungs, ears, kidneys and with your fertility.
- Neurological problems.
- Changes in mood and feelings.
- Changes in thinking, learning, or memory.
- Another type of cancer.
