Chondrosarcoma, also known as chondrogenic sarcoma, is one of the most common types of bone cancer, and develops from the cartilage on the end of bones. Chondrosarcomas are most commonly found in the femur (thigh bone), shoulder, hip, or pelvis, but can also develop in the knees, ribs, skull, spine, and windpipe (trachea).

Cartilage is smooth, connective tissue that protects and lines joints and the ends of bones. There are three main types of cartilage in the body: hyaline, elastic, and fibrocartilage. Hyaline cartilage, also known as articular cartilage, is the most abundant type of cartilage in the body, and generally 2-4mm thick. It is most commonly found in the joints and on the ends of bones, and is slippery and smooth in order to help your bones move smoothly past each other. Hystine cartilage is most commonly found in the ribs, nose, ears, larynx (throat), trachea (windpipe), and on the ends of bones. Elastic cartilage, also known as yellow fibrocartilage, is less abundant, and supports the parts of the body that need to move to function. It is able to return to its original shape when moved, and is most commonly found in the ear and larynx. Fibrocartilage is a dense and generally stronger than the other types of cartilage. Its primary function is support weight-bearing areas of the body, and is most commonly found in the intervertebral discs of the spine and the meniscus of the knee. Most chondrosarcomas develop from hyaline cartilage. 

Chondrosarcomas are often confused with another type of bone cancer known as osteosarcoma. Osteosarcoma, or osteogenic sarcoma, is the most common type of bone cancer that is usually found in the ends of long bones, such as the shin, femur (thigh bone) and humerus (upper arm bone). However, unlike chondrosarcoma, osteosarcomas develop from osseous (or bone) cells as opposed to cartilage. For more information on osteosarcomas, please visit the rare cancers Australia osteosarcoma page.

Chondrosarcomas are generally diagnosed equally among the sexes, and tends to be diagnosed in people over 40 years old. However, anyone can develop this disease.

Types of Chondrosarcoma

There are several different types of chondrosarcoma, which are categorised based on the types of cells they originate from.

Conventional Chondrosarcoma

Conventional chondrosarcomas are the most common subtype of this disease. There are several different types of conventional chondrosarcomas, which are classified by their location.

Central Chondrosarcoma

Central chondrosarcomas are the most common type of conventional chondrosarcoma, and generally arise within the medullary cavity (the central, hollow portion of the bone that contains bone marrow). This type of tumour is slightly more common in males, and often affects the femur, pelvis, or humerus. Central chondrosarcomas can be aggressive, but can have a good prognosis when caught early.

Secondary Peripheral Chondrosarcoma

Secondary peripheral chondrosarcoma is a less common subtype of central chondrosarcoma that has metastasised (or spread) from an existing osteochondroma (a benign or non-cancerous bone tumour). This type of tumour tends to be diagnosed in patients under 50 years old, and generally affects the pelvis or the shoulder. Secondary peripheral chondrosarcomas can be aggressive, but can have a good prognosis when caught early.

Periosteal/Juxtacortical Chondrosarcoma

Periosteal chondrosarcomas, also known as juxtacortical chondrosarcomas, are a very rare subtype of central chondrosarcomas that tend to affect the femur. Unlike other chondrosarcomas, these tumours are slightly more common in men and tend to affect people between the ages of 20-40. Although these tumours can be aggressive, they often have a good prognosis.

Clear Cell Chondrosarcoma

Clear cell chondrosarcoma is a less common type of chondrosarcoma that generally develops from the epiphysis (the rounded end of the long bone) of the humerus or femur. Unlike most types of chondrosarcoma, these tumours are significantly more common in men, and generally affect people between the ages of 30-50. These tumours are generally nonaggressive, and can have a good prognosis.

Myxoid Chondrosarcoma

Myxoid chondrosarcoma is a rare type of chondrosarcoma that can affect both bone and soft tissue. They most commonly develop in the deep soft tissue of the thigh and other extremities, and tend to affect people between the ages of 30-60 with a slight predilection for men. While this subtype can be aggressive, it can have a good prognosis when found early.

Mesenchymal Chondrosarcoma

Mesenchymal chordosarcomas are a rare and highly aggressive subtype of chondrosarcomas that commonly develop in facial bones, ribs, pelvic bone, and spine. Unlike other chondrosarcomas, this subtype tends to affect people between the ages of 25-30. Mesenchymal chondrosarcomas are very aggressive, and may not have as good of a prognosis as other types of chondrosarcomas.

Dedifferentiated Chondrosarcoma

Dedifferentiated chondrosarcomas are a rare and highly aggressive subtype of chondrosarcoma that generally develop in the pelvis, femur, or humerus. It generally affects people between the ages of 50-60, and may spread to nearby soft tissue. Dedifferentiated chondrosarcomas are very aggressive, any may not have as good of a prognosis as other types of chondrosarcoma.

Enchondroma

Enchondromas are a relatively common hyaline cartilage tumour that generally develops in the hands and feet, but can also develop in the femur, humerus, or the tibia and fibula. Unlike other tumours, enchondromas generally develop between the ages of 10-20. Enchondromas are benign (non-cancerous), however they may become cancerous if left untreated.

Treatment 

If a chondrosarcoma is detected, it will be staged and graded based on size, metastasis (whether the cancer has spread to other parts of the body) and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you.

Cancers can be staged using the TNM staging system:

• T (tumour) indicates the size and depth of the tumour.
• N (nodes) indicates whether the cancer has spread to nearby lymph nodes.
• M (metastasis) indicates whether the cancer has spread to other parts of the body.

This system can also be used in combination with a numerical value, from stage 0-IV:

• Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
• Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
• Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localised cancer.
• Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
• Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advanced or metastatic cancer.

Cancers can also be graded based on the rate of growth and how likely they are to spread:

• Grade I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
• Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour. 
• Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour. 

Once your tumour has been staged and graded, your doctor may recommend genetic testing, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you. 

Treatment is dependent on several factors, including location, stage of disease and overall health. 

Treatment options for chondrosarcomas may include:

• Surgery, potentially including:
  • Wide en bloc resection.
  • Curettage (cancer is scraped out with a small, sharp instrument called a curette).
  • Limb-sparing surgery (surgery to remove the cancer only and salvage the limb).
  • Amputation (removal of all or part of the affected limb).
  • Bone graft (a portion of bone from another part of the body or another person is used to replace the bone lost to cancer).
• Radiation therapy.
• Chemotherapy.
• Cryotherapy.
• Clinical trials.
• Palliative care.

For more information on the treatment options, please refer to the Rare Cancers Australia Treatment Options page.

Risk factors 

While the cause of chondrosarcomas remains unknown, the following factors may increase the likelihood of developing the disease:

• Ollier’s disease (also known as enchondromatosis).
• Maffucci syndrome.
• Multiple hereditary exostoses (MHE).
• Wilms’ tumour.
• Paget’s disease.
• Li-Fraumini syndrome.
• Previous treatment with chemotherapy.
• Previous treatment with radiation therapy.

Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned. 

Early symptoms 

Symptoms of a chondrosarcoma may include:

• Large mass on a bone.
• Pressure surrounding mass in affected area.
• Pain that gets worse overtime or at night.
• Weakness in affected area.
• Limited movement in affected area.
• Swelling of affected area.
• Joint stiffness in affected area.
• Changes in bowel and/or bladder habits (chondrosarcomas of the pelvis).

Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned. 

Diagnosis/diagnosing 

If your doctor suspects you have a chondrosarcoma, they may order the following tests to confirm the diagnosis and refer you to a specialist for treatment. 

Physical examination 

Your doctor will collect your overall medical history, as well as your current symptoms. Following this, they may examine your body to check for any abnormalities. 

Imaging & blood tests 

The doctor will take images of your body using magnetic resonance imaging (MRI), a computed tomography scan (CT scan), and/or positron emission tomography (PET scan), depending on where it is suspected the cancer is. The doctor may also look at other parts of the body and looks for signs of metastasis. Additionally, a blood test may be taken to assess your overall health and help guide treatment decisions. 

Biopsy

Once the location(s) of the cancer has been identified, the doctor will perform a biopsy to remove a section of tissue using a needle. The tissue sample will then be analysed for cancer cells. This can be done by a fine needle aspiration (FNA) or a core needle biopsy (CNB).

Prognosis (Certain factors affect the prognosis and treatment options) 

While it is not possible to predict the exact course of the disease, your doctor may be able to give you a general idea based on the rate and depth of tumour growth, susceptibility to treatment, age, overall fitness, and medical history. Generally, early-stage chondrosarcomas have a better prognosis and survival rates. However, if the cancer is advanced and has spread, the prognosis may not be as good and there may be a higher risk of cancer recurrence. It is very important to discuss your individual circumstances with your doctor to better understand your prognosis. 

References 

• Australian Cancer Research Foundation (ACRF)
• The Liddy Shriver Sarcoma Initiative
• Radiopaedia
• UpToDate

^{Some references are to overseas websites. There may be references to drugs and clinical trials that are not available here in Australia.}