What is Chondrosarcoma?
Chondrosarcomas are a type of cancer that affects cartilage and take on various shapes and behaviors. Roughly 20% of all primary bone cancers are chondrosarcomas. They are usually found in the pelvis or long bones. There are two types: primary, which develops in healthy bones, and secondary, which begins in an existing benign condition of the cartilage or bone. The majority of chondrosarcomas, about 85%-90%, are considered primary and are further divided into central, periosteal, and peripheral subtypes. There are also non-typical versions of chondrosarcoma that include clear cell chondrosarcoma, mesenchymal chondrosarcoma, and dedifferentiated chondrosarcoma. Diagnosing chondrosarcoma is typically straightforward based on its unique features in medical imaging.
What Causes Chondrosarcoma?
Most of the time, chondrosarcomas, a type of bone cancer, occur randomly. However, they can sometimes develop from benign bone conditions called osteochondromas and enchondromas. It’s important to note that about 5% of osteochondromas, whether they’re in multiple or solitary forms, can turn malignant.
Risk Factors and Frequency for Chondrosarcoma
Primary central chondrosarcoma is a type of cancer that affects the bones. It is the third most common type of bone cancer, after myeloma and osteosarcoma. This condition mostly occurs in adults over 50 years old and is slightly more common in men than in women.
- Primary central chondrosarcoma is the third most prevalent type of bone cancer.
- This type of cancer is more common in adults over 50 years old.
- It’s slightly more common in males.
- The cancer often impacts the bones within the middle part of the body, like the pelvis, scapula, sternum, and ribs.
- It can also affect the upper part of the thigh bone (proximal femur) and the upper part of the upper arm bone (proximal humerus).
- The hands and feet are rarely affected.
Signs and Symptoms of Chondrosarcoma
People with tumors often experience swelling and discomfort as the main symptoms. These symptoms can last for a long time, from several months to even years. If the tumor is located at the base of the skull, it may cause symptoms related to the nervous system.
Testing for Chondrosarcoma
Plain radiography, often the first step in evaluation, allows doctors to identify the nature and severity of the lesion. It may show lytic lesions in half of the cases and internal calcifications, often described as popcorn or rings and arcs calcifications, in around 70% of cases. Other possible indications may include inner bone scalloping, and in severe cases of chondrosarcoma, a worm-eaten or permeative appearance or signs of bone remodeling.
A Computed Tomography (CT) scan can highlight matrix calcification in a vast majority of cases (94%). CT scans can also help detect endosteal scalloping and breaches in the cortical bone, which are seen in around 90% of long bone chondrosarcoma cases. The lesion, when injected with a contrast dye, might exhibit uneven enhancement.
Magnetic Resonance Imaging (MRI) typically shows a lobulated lesion. This is seen as a bright or “high” signal on T2 images and a lower or mid-level signal on T1-weighted images.
Lastly, a tissue biopsy is crucial to confirm chondrosarcoma and differentiate it from other types of bone tumors, benign or malignant. For the most reliable results, the sample should be taken from the most aggressive part of the tumor as indicated by the imaging results.
Treatment Options for Chondrosarcoma
The choice of treatment for chondrosarcoma, which is a type of cancer, mainly depends on where the tumor is located and how aggressive it is. The first and primary method of treating chondrosarcoma is through surgery. When dealing with less aggressive, or low-grade, central chondrosarcoma, a procedure called intralesional curettage is often used. This process involves scraping out the tumor, using a special surgical tool to grind it down, and applying a substance like hydrogen peroxide to aid in killing any remaining cancer cells.
If the tumor is larger, reaches into the joint or soft tissue, or is located in challenging areas like the spine or pelvis, a more extensive surgical approach is needed. In these cases, or when dealing with moderate to highly aggressive chondrosarcoma, a comprehensive removal of the tumor, known as an en bloc excision, is usually the preferred surgical approach.
Chemotherapy, usually a common treatment for other types of cancer, is generally not effective for dealing with conventional chondrosarcoma. Nonetheless, it may be useful for handling specific cases where the chondrosarcoma has an extra-aggressive component known as a high-grade spindle cell.
Radiation therapy, another common cancer treatment, can be used to manage chondrosarcoma in certain situations. If the surgery was unable to remove all of the high-risk chondrosarcoma, radiation therapy can help reduce the risk of the cancer returning. Radiation therapy is also used for tumors of moderate to high aggression and for tumors located in areas where surgery would be complicated or restricted. It can even be considered the primary method of treatment if the tumor can’t be removed through surgery.
What else can Chondrosarcoma be?
- Chondromyxoid fibroma (a type of bone tumor)
- Enchondroma (another type of benign bone tumor)
- Chondroblastic osteosarcoma (a more aggressive type of bone cancer)
- Fracture callus (the healing tissue that forms around a break in the bone)
What to expect with Chondrosarcoma
The histological grade, or the microscopic examination of cancer cells, is the most crucial determinant of local recurrence and cancer spread. Low-grade chondrosarcomas, a type of bone cancer that grow slowly and rarely spread to other areas, typically have a favorable outcome. For these cancers, the 5-year survival rate is 83%.
However, high-grade or dedifferentiated chondrosarcomas, which grow rapidly and are more likely to spread early, have a less favorable outcome. For these types, the 5-year survival rate drops to 53%.
Possible Complications When Diagnosed with Chondrosarcoma
The tumor can come back after treatment. It can also spread to other parts of the body – a process called metastasis. The most common place for this cancer to spread to is the lungs. How likely the cancer is to spread or come back depends on how aggressive (its grade) it is:
- Low-grade: less than 10% chance of metastasis
- Intermediate-grade: 10% to 50% chance of metastasis
- High-grade: 50% to 70% chance of metastasis
Preventing Chondrosarcoma
It’s important for patients and their families to learn how to spot the early signs of bone tumors. If a patient is experiencing bone pain, bone or joint swelling, or if they can feel a lump on their bones, they should seek medical help as soon as possible. The primary treatment for a type of bone tumor called chondrosarcoma is surgery. There is a chance that the tumor could come back after the surgery, so it’s recommended that these patients have regular check-ups in the long term to keep a close watch on their condition.