Chondrosarcoma, or CS, is a group of bone tumors that are made up of cells that make too much cartilage. Cartilage is the tough and flexible tissue that makes up several structures throughout the body, like the ears and nose. Cartilage also covers the ends of the bones and provides a cushion between the places where bones meet. 

The most common type of chondrosarcoma, called conventional chondrosarcoma, usually grows very slowly. Rare subtypes of chondrosarcoma, called dedifferentiated chondrosarcoma, myxoid chondrosarcoma, clear cell chondrosarcoma, and mesenchymal chondrosarcoma, may grow more quickly and may spread to other parts of the body. 

CS is a rare type of bone tumor and affects 1 person per 200,000 per year in the US. It is more common in adults. The rare subtypes of chondrosarcoma make up only about 10% of all CS cases.

We know that in some cases of CS, chromosomes (the structures in your cells that contain all of your genes) break apart and get put back together in the wrong way. This can cause cells to not function like they should. In some cases of CS, a gene called EWSR1 joins with a gene called NRA3. In some cases of CS, there are changes in the genes IDH1/2 and/or COL2A1.

The genetic condition multiple osteochondroma, which can run in families, can lead to CS in about 15% of cases. 

Symptoms of CS can differ depending on where the tumor is growing. Symptoms can include:

• Pain that does not go away with rest
• Swelling
• A large mass on the affected bone

Imaging: If you have symptoms of CS, your doctor will use imaging scans such as CT and MRI to look at where the tumor is and how big it is. They will also check for signs that the tumor has spread to other parts of the body.

Biopsy: To check if the tumor is CS, your doctor will do a biopsy, taking a small sample from the tumor with a needle. An expert, called a pathologist, will study cells from the sample under the microscope to see what kind of tumor it is. 

Getting the correct diagnosis is very important to get the right treatment.

Treatment for each patient will be unique. You should go to an expert in sarcoma treatment to decide the best approach for your tumor.

Treatment options to discuss with your doctor include: 

Surgery: Surgery is used to remove as much of the CS as possible. Small conventional CS can be cured with surgery.

Cryosurgery: Cryosurgery is a type of surgery that uses a very cold liquid to damage the tumor tissue. 

Radiation therapy: Radiation therapy is a treatment option for some CS tumors that cannot be removed by surgery. 

Chemotherapy: When surgery is not possible or when the cancer has spread, chemotherapy can be used to treat CS. Chemotherapy is usually not helpful in most cases of CS because these tumors grow very slowly. In rare cases of CS when the tumor grows faster, chemotherapy may help treat the tumor, but there are so few cases that it is not clear if chemotherapy works well.

The estimate of how a disease will affect you long-term is called prognosis. Every person is different and prognosis will depend on many factors, such as: 

• Where the tumor is in your body
• If the cancer has spread to other parts of your body
• How much of the tumor was taken out during surgery 

If you want information on your prognosis, it is important to talk to your doctor.

Doctors estimate CS survival rates by how groups of people with CS have done in the past. Because there are so few CS patients, these rates may not be very accurate. 

The average 5-year survival rate for patients with CS is different depending on the subtype of CS the patient has. Different types of CS may grow more quickly or come back after the tumor is removed. In cases where the tumor grows back, called recurrence, or has spread to other parts of the body, the survival rate may be lower.