Chondrosarcoma Metastatic

Chondrosarcoma with metastatic disease represents a serious form of bone cancer where the tumor has spread beyond its original location to other parts of the body, most commonly the lungs and other bones, presenting significant challenges for treatment and survival.

Table of contents

• What is Chondrosarcoma
• Understanding Metastatic Spread
• Risk Factors and Causes
• Symptoms
• Diagnosis
• Treatment Approaches
• Prognosis and Survival

What is Chondrosarcoma

Chondrosarcoma is a type of bone cancer that starts in cartilage cells. Cartilage is the smooth connective tissue that protects the ends of bones and lines most joints^[1]. This cancer mainly affects the cartilage cells of the thighbone, shoulder, or pelvis, and less often starts in the knee, ribs, skull, and windpipe^[1].

Chondrosarcoma is the second most common type of primary bone cancer in adults^[1]. A primary bone cancer is one that starts from bone cells, which is different from cancer that starts in another organ and then spreads to the bone^[1]. This disease accounts for about 20% of all primary malignant tumors of the bone^[2].

There are different types of chondrosarcomas, with conventional chondrosarcoma accounting for 85% to 90% of cases^[2]. Other types include dedifferentiated chondrosarcoma, clear cell chondrosarcoma, and mesenchymal chondrosarcoma^[2]. These different types vary in how aggressively they grow and their likelihood of spreading to other parts of the body.

Understanding Metastatic Spread

When cancer cells grow into nearby areas or spread to other parts of the body, this is called metastasis^[1]. In chondrosarcoma, the most common places the cancer spreads are the lungs and other bones^[5][16].

The risk of metastasis is highly dependent on the grade of the tumor. Chondrosarcomas can be classified into three grades based on how the cells look under a microscope. Grade 3 chondrosarcoma carries a greater than 60% risk of metastasis, grade 2 carries a risk of approximately 20%, and low-grade chondrosarcoma rarely metastasizes^[5][16]. The higher the grade, the more likely the tumor is to spread^[8].

Chondrosarcomas vary widely in their behavior. Low-grade tumors are not very aggressive and present a low risk of spreading to other parts of the body. On the other end of the spectrum, high-grade chondrosarcomas and certain subtypes are aggressive and present a significant risk of spread to other areas^[5][16].

Risk Factors and Causes

The exact cause of chondrosarcoma is not known. There may be a genetic change that makes some people more likely to have this cancer^[1]. The majority of chondrosarcomas are sporadic, but they may develop from the malignant transformation of benign bone tumors^[2].

Chondrosarcoma is rare in people younger than age 20. Risk goes up with age, with the majority of patients older than 50 years of age at diagnosis^[2]. Most often, chondrosarcoma starts in normal cartilage cells, but it may also start in a noncancer (benign) bone or cartilage tumor^[1].

Several benign conditions may be present when chondrosarcoma develops. Enchondroma is a type of benign bone tumor that starts in cartilage and often affects the hands^[1]. Ollier disease causes clusters of enchondromas that often affect the hands and feet, and about 1 out of 3 people with this condition develop chondrosarcoma^[1]. Maffucci syndrome causes many enchondromas and increases the risk of chondrosarcoma^[1]. Multiple hereditary exostoses is a syndrome passed in families that causes bone defects which can develop into chondrosarcoma^[1].

Symptoms

Most chondrosarcomas grow slowly, causing symptoms that take months to develop^[3]. Chondrosarcoma tends to grow slowly, so it might not cause signs and symptoms at first^[4].

The most common symptoms include bone pain that comes and goes and gets worse at night, fatigue, and a swollen spot or lump on a bone^[3]. Patients typically present with pain and swelling or a noticeable mass that can be seen or felt. The pain is often described as deep and aching. Pain can be constant or intermittent and occur at rest or with activity. Nighttime pain that can make it difficult to sleep is more common in larger and more aggressive tumors^[5][16].

When chondrosarcoma occurs, symptoms depend on where the tumor is and how big it is. A large lump on a bone, feeling of pressure around the lump, pain that gets worse over time, weakness and limited movement in a limb or joint, local swelling, and joint stiffness may occur^[7]. Tumors in the pelvis can cause bowel and bladder problems^[7].

Diagnosis

A healthcare provider will ask about symptoms and do a physical exam. X-rays are the initial imaging test of choice. X-rays give clues to the type of tumor and how aggressive the tumor is^[5][16].

If chondrosarcoma is suspected, imaging is completed to see if the cancer has spread anywhere else and to precisely see the local extent of the disease. These tests include a magnetic resonance imaging (MRI) of the primary site where the cancer started, computed tomography (CT) scan of the chest, and a bone scan^[5][16].

In most cases, a biopsy to confirm the diagnosis will be performed with a needle^[5][16]. An orthopaedist may remove tissue from a suspicious lump or the entire lump. A pathologist will examine the tissue for signs of cancerous cells^[3].

If cells are cancerous, the pathologist will identify the tumor type and establish a tumor grade. Chondrosarcomas can be classified into three histologic grades, depending on findings of cellularity and how abnormal the cells appear. Grade I is low grade, Grade II is intermediate grade, and Grade III is high grade^[8].

Treatment Approaches

Surgery is the primary treatment for any chondrosarcoma^[12][16]. Complete, wide surgical removal of the chondrosarcoma is the preferred method when it is feasible. Success depends on the stage of the disease, with low-grade tumors offering the best prognosis after complete surgical removal with clear margins^[12].

For metastatic chondrosarcoma, lesions with isolated pulmonary metastasis (spread to the lungs only) can still be surgically removed if removal of the isolated lung lesion is feasible^[12]. Surgery may be used for tumors that are newly diagnosed and tumors that have come back^[14].

Radiotherapy and chemotherapy play limited roles in primary treatment. An exception is their use as adjuvant therapy (additional treatment after surgery) or palliative treatment in surgically inaccessible areas^[12]. Diffuse metastasis is usually an indication for systemic radiotherapy or chemotherapy, though the results are generally poor^[12].

Chemotherapy is sometimes offered for certain types. Mesenchymal chondrosarcoma may be treated with chemotherapy after surgery. If mesenchymal chondrosarcoma has already metastasized at the time of diagnosis, certain drug combinations may be used^[14]. Dedifferentiated chondrosarcoma may be treated with the same chemotherapy drug combinations that are used for osteosarcoma^[14].

Radiation therapy can be used alone but is typically used after surgical removal of the tumor. Chondrosarcomas are more resistant to radiation therapy than other tumor types, so higher doses may be required^[14]. Radiation therapy is typically only used in situations where a tumor is deemed untreatable with surgery^[5][16].

Prognosis and Survival

Chondrosarcoma with metastatic disease has a very poor prognosis^[6][22]. The risk of metastasis and survival outcomes are highly dependent on several factors, including the grade of the tumor and its location.

Location of the tumor is an important variable that must be considered. Tumors in the pelvis often grow to larger sizes before they are detected and are more difficult to remove surgically. As a result, they have a higher risk of metastasis and local recurrence^[5][16].

Different types of chondrosarcoma have different prognoses. Dedifferentiated chondrosarcoma, which is a fast-growing type, has particularly poor outcomes, with a 1-year survival rate of only 10%^[12].

Overall, about 79% of people with chondrosarcoma are alive five years after diagnosis^[20]. However, this varies significantly based on whether the disease has spread. Patients with metastatic disease at diagnosis face much more challenging prospects.

Due to the rare and complex nature of this disease, patients should seek out evaluation and treatment from an orthopaedic oncologist who specializes in treating this diagnosis. Often, there are discussions with other doctors on the team who can provide their expertise on chemotherapy and radiation^[5][16].