What is Chondrosarcoma?

Overview

Chondrosarcoma is a rare form of malignant bone cancer that develops in cartilage cells. Cartilage is a tough and flexible tissue that makes up several structures throughout the body including the ends of bones (hyaline cartilage), the ears and the nose. Chondrosarcomas are large tumours found in the bone or the surrounding soft tissue. 

Chondrosarcoma primarily affects the skeletal system, most commonly occurring in the pelvis, thigh bone, shoulder and ribs. The cancer exhibits a diverse range of symptoms, depending on its size and location. Patients may experience persistent pain, swelling, or the development of a visible lump near the affected area. In some cases, chondrosarcoma remains asymptomatic until it reaches an advanced stage or causes fractures.

Diagnosis typically involves a combination of imaging tests, such as X-rays, CT scans, and MRI scans, along with a biopsy to confirm the presence of cancerous cells. Treatment options for chondrosarcoma include surgery, radiation therapy and chemotherapy.

Given the aggressive nature of chondrosarcoma, early detection and prompt intervention are crucial for improving treatment outcomes and prognosis. Close monitoring and ongoing medical care are often necessary to manage this challenging malignancy effectively.

Types of chondrosarcoma

Chondrosarcoma encompasses several distinct subtypes. The classification is based on various factors, including the tumours' histological appearance (structure under a microscope), location and molecular characteristics (indications of cancer in the cell). The main types of chondrosarcoma are as follows:¹

• Conventional/Primary Chondrosarcoma: The most common type, accounting for approximately 85% of all cases. It typically arises in the hollow part of long bones, such as the femur (thigh bone)  and humerus (upper arm bone) and exhibits a range of histological grades from 1-3 depending on the severity of the cancer
• Dedifferentiated Chondrosarcoma: Characterised by the coexistence of conventional chondrosarcoma and a high-grade sarcoma component (often classified as grade 4 chondrosarcoma). This subtype has a poorer prognosis compared to conventional chondrosarcoma due to its aggressive nature
• Clear Cell Chondrosarcoma: A rare variant that affects the expanded/rounded ends of long bones, such as the femur and humerus. It is characterised by the presence of clear tumour cells and typically exhibits less aggressive behaviour compared to other types
• Mesenchymal Chondrosarcoma: A rare and aggressive subtype that occurs predominantly in young adults. It commonly affects the bones of the pelvis, ribs and skull. It is characterised by a combination of small round cells and islands of hyaline cartilage
• Extraskeletal Chondrosarcoma: arises from soft tissues rather than bone. It typically occurs in the extremities and trunk, often near tendons or joint capsules

Causes of chondrosarcoma

Damage to the genes (DNA) within cells can disrupt their normal division and growth, leading them to grow and multiply at an abnormally fast rate which causes cancer. The reason behind this damage in most cases is still unclear. The main types of faulty genes that cause cancer are tumour suppressor genes, oncogenes and DNA repair genes. 

In some instances, chemotherapy or radiotherapy for other tumours in young patients can cause DNA damage to induce chondrosarcoma. 

 Some risk factors of chondrosarcoma include:

• Genetic Alterations: Certain genetic mutations and chromosomal abnormalities have been associated with the development of chondrosarcoma. Mutations in genes such as IDH1, IDH2, and TP53 have been associated with this disease
• Hereditary Conditions: Multiple hereditary exostoses (MHE), also known as hereditary multiple osteochondromas, are linked to an increased risk of developing chondrosarcoma. MHE is characterized by the presence of multiple benign bone tumours (osteochondromas) that have the potential to transform into chondrosarcoma
• Prior Radiation Therapy: Individuals who have received radiation therapy for the treatment of other cancers or conditions may be at a higher risk of developing chondrosarcoma in the irradiated area
• Age and Gender: Chondrosarcoma predominantly affects adults, with the incidence increasing with age. It is more commonly seen in males than females

It is important to note that these factors are associated with an increased risk, but not everyone with these risk factors will develop chondrosarcoma. Further research is needed to fully elucidate the underlying causes and risk factors associated with chondrosarcoma.

Signs and symptoms of chondrosarcoma

Chondrosarcoma can exhibit a range of signs and symptoms that vary depending on the tumour's location, size, and aggressiveness. The following are common signs and symptoms associated with chondrosarcoma:

• Pain: persistent pain in the affected bone or joint is a common symptom of chondrosarcoma. The pain may initially be mild and intermittent but can gradually worsen over time
• Swelling and Lump: Chondrosarcoma may cause localised swelling and the development of a visible lump or mass near the affected area. The lump may be firm and hard to the touch
• Limited Range of Motion: Depending on the location of the tumour, chondrosarcoma can impede joint movement, resulting in a reduced range of motion
• Fractures: Chondrosarcoma weakens the affected bone, making it more susceptible to fractures or breaks, even with minimal trauma
• Additional symptoms: Chondrosarcoma located near nerves or blood vessels may cause additional symptoms such as numbness, tingling or weakness in the affected limb.

It is important to note that these symptoms are not exclusive to chondrosarcoma and can be present in other bone and joint conditions. Proper medical diagnosis through imaging and biopsy, is necessary to establish an accurate prognosis.

Management and treatment for Chondrosarcoma

The management and treatment of chondrosarcoma involves a multidisciplinary approach tailored to the individual patient's specific circumstances.² Treatment options for chondrosarcoma include:

• Surgery: The primary treatment for chondrosarcoma, surgery aims to remove the tumour while preserving limb function. The surgical approach may involve wide local excision, where the tumour and a margin of surrounding healthy tissue are removed, or in some cases, amputation may be necessary for tumours in challenging locations
• Radiation Therapy: May be recommended as an adjuvant treatment following surgery to target any remaining cancer cells or as palliative therapy to relieve pain and control tumour growth in unresectable (unable to be removed with surgery) cases. It involves the use of high-energy radiation to destroy cancer cells
• Chemotherapy: Generally less effective in treating chondrosarcoma compared to other types of cancer. However, it may be considered in certain cases, particularly for dedifferentiated chondrosarcoma or when the tumour has metastasised to other sites in the body
• Targeted Therapies: Emerging targeted therapies, such as inhibitors of the isocitrate dehydrogenase (IDH) mutation that is commonly found in chondrosarcoma, are being investigated in clinical trials and may offer promising treatment options in the future

Diagnosis of Chondrosarcoma

The diagnosis of chondrosarcoma involves a comprehensive evaluation that incorporates various diagnostic techniques. The following are common methods used in the diagnosis of chondrosarcoma:

• Imaging: Plays a crucial role in identifying and characterising chondrosarcoma. X-ray provides initial information about the presence of a bone lesion. Additional imaging techniques, such as computed tomography (CT) scans and magnetic resonance imaging (MRI) provide a more detailed visualisation of the tumour, its size, location, and involvement of nearby structures
• Biopsy: Essential for confirming the diagnosis of chondrosarcoma. It involves the extraction of a tissue sample from the area, which is then examined under a microscope by a pathologist. The biopsy helps determine the grade, subtype, and malignant nature of the tumour
• Histopathological Analysis: The tissue sample obtained from the biopsy is subjected to histopathological analysis, where it is examined for specific features that characterise chondrosarcoma, including the presence of malignant cartilage cells, nuclear atypia (abnormal appearance of nucleus - part of the cell that contains the DNA) and invasiveness into the surrounding tissues
• Molecular Testing: May be performed to detect specific genetic mutations or chromosomal abnormalities that are associated with chondrosarcomas such as IDH1 and IDH2 mutations

Accurate diagnosis is critical for appropriate treatment planning and determining the prognosis of chondrosarcoma. It is important for patients suspected of having chondrosarcoma to be evaluated by a team of specialised healthcare professionals, including orthopaedic surgeons, radiologists and pathologists.

FAQs

How can I prevent Chondrosarcoma?

Unfortunately, there are no known preventive measures specifically for chondrosarcoma. As the exact cause of chondrosarcoma is not fully understood, there are no established strategies to prevent its development. However, maintaining overall good health, following a balanced diet, engaging in regular physical activity, and avoiding exposure to known risk factors for cancer, such as tobacco and certain environmental toxins, may contribute to reducing the overall risk of developing various types of cancers, including chondrosarcoma.

How common is Chondrosarcoma?

Chondrosarcoma is considered a relatively rare form of cancer with around 190 newly diagnosed cases each year in the UK. Its incidence varies depending on the population studied and the specific subtype of chondrosarcoma. The incidence rate in England is around 2.9 people affected per 1 million people of the population.

Who is at risk of Chondrosarcoma?

While chondrosarcoma can affect anyone, certain factors may increase the risk of its development. Some risk factors are detailed in ‘Causes of Chondrosarcoma’.

When should I see a doctor?

If you experience persistent bone pain, swelling or the development of a visible lump near a bone or joint, it is important to consult a healthcare professional for further evaluation. While these symptoms may not necessarily indicate chondrosarcoma, they should be investigated to determine the underlying cause and provide appropriate medical care. Early detection and timely intervention are crucial for better treatment outcomes.

Summary

Chondrosarcoma is a rare form of cancer that originates in cartilage cells. The incidence of chondrosarcoma is relatively low with around 190 new cases diagnosed in the UK. It can occur at any age but is more commonly diagnosed in adults. Individuals with hereditary conditions such as multiple hereditary exostoses (MHE) and those who have undergone prior radiation therapy are at a higher risk. If persistent bone pain, swelling or the presence of a lump near a bone or joint occurs, it is important to consult a healthcare professional for further evaluation. Early detection and appropriate medical intervention are essential for optimal treatment outcomes.