Chondrosarcoma

Chondrosarcoma is a rare type of bone cancer that begins in cartilage, the connective tissue protecting joints and bones. It grows slowly in most cases, but certain types can be aggressive and difficult to treat. Understanding the symptoms, causes, and treatment options is essential for anyone affected by this condition.

Table of contents

• What is chondrosarcoma?
• Types of chondrosarcoma
• Signs and symptoms
• Causes and risk factors
• How doctors diagnose chondrosarcoma
• Treatment options
• Outlook and survival

What is chondrosarcoma?

Chondrosarcoma is a rare type of cancer that usually begins in the bones, but can sometimes occur in the soft tissue near bones. This cancer develops in cartilage, which is the tough, flexible tissue that cushions joints and helps form certain parts of the body^[1]. Chondrosarcomas are very rare, affecting about 1 in 200,000 people in the United States^[4].

This cancer accounts for about 20% of all primary malignant tumors of the bone, making it the third most common primary bone cancer after myeloma and osteosarcoma^[3]. Chondrosarcoma most often develops in the pelvis, hip, and shoulder, though it can also appear in the ribs, arms, legs, breastbone, and spine^[1][4].

• Pelvis
• Hip bones
• Shoulder bones
• Thigh bone (femur)
• Upper arm bone (humerus)
• Ribs
• Breastbone
• Spine

Types of chondrosarcoma

There are different types of chondrosarcomas, and understanding which type a person has helps doctors plan the best treatment approach.

Conventional chondrosarcoma is the most common type, accounting for more than 85% of all cases^[3][4]. This type develops in the thigh bone, upper arm bone, or pelvis and typically grows slowly, making it less likely to spread to other parts of the body than other types^[4].

Dedifferentiated chondrosarcoma is a fast-growing type that usually develops in the upper arm bone, thigh bone, or pelvis^[4]. In this type, some cells start out as typical chondrosarcoma cells, but then parts of the tumor change into cells that resemble high-grade sarcoma, which tends to grow and spread quickly^[4].

Clear cell chondrosarcoma is typically found near a joint in the arm or leg. These tumors tend to grow slowly and rarely spread to other areas^[4].

Mesenchymal chondrosarcoma usually develops in the spine, ribs, or jaw^[4]. These tumors often grow quickly and are more likely to spread than other chondrosarcomas. They also have a higher chance of coming back after treatment. This type represents about 2% of chondrosarcoma cases^[6].

Signs and symptoms

Chondrosarcoma tends to grow slowly, so it might not cause signs and symptoms at first. Many people with this cancer appear to be in good health, and patients are often not aware of the growing tumor until there is a noticeable lump or pain^[6]. Because symptoms develop gradually, they may take months to appear^[4].

The most common symptoms include bone pain that comes and goes and gets worse at night^[1][4]. Many patients experience fatigue and unintentional weight loss^[4]. A swollen spot or lump on a bone, such as on the arm, leg, or ribs, may develop^[4].

When chondrosarcoma occurs, signs and symptoms may include a growing lump or area of swelling, increasing pain, and weakness or bowel and bladder control problems if the cancer presses on the spinal cord^[1]. Some patients may experience decreased movement of the affected limb or a limp^[7].

These symptoms don’t always mean bone cancer. However, if you have a lump that doesn’t go away within two weeks or you feel exhausted all the time, it’s important to talk to a healthcare provider who can find out what’s causing your symptoms^[4].

Causes and risk factors

It’s not clear what causes chondrosarcoma. Doctors know that cancer begins when a cell develops changes, called mutations, in its DNA^[1]. A cell’s DNA contains the instructions that tell it what to do. The instructions tell the cell to multiply quickly and to continue living when healthy cells would die. The accumulating cells form a tumor that can grow to invade and destroy normal body tissue^[1].

The majority of chondrosarcomas are sporadic, but they may develop from the malignant transformation of osteochondromas (benign bone tumors) and enchondromas (benign cartilage tumors)^[3]. Malignant transformation occurs in 5% of osteochondromas^[3].

Researchers have linked the condition to several genetic disorders. People with Li Fraumeni syndrome are likely to develop cancerous tumors, including chondrosarcomas^[4]. Maffucci syndrome and Ollier’s disease cause benign tumors in cartilage, bone, and skin, which may increase the risk^[1][4]. Hereditary multiple osteochondromas are multiple benign bone tumors that can disrupt bone growth^[4].

Medical experts think that in some cases, a change in a chromosome or gene that’s unrelated to an inherited disorder may change cartilage cells^[4]. Studies have shown that chromosomal anomalies detected in some types of chondrosarcomas include changes in specific areas of chromosomes^[3].

Chondrosarcoma is a tumor of adulthood and older age. You can develop chondrosarcoma at any age, but the condition is more common in people ages 40 to 75^[4]. Most people receive a diagnosis at age 51^[4]. The majority of patients are older than 50 years of age at diagnosis, with a slight male predominance^[3]. Rarer forms, like mesenchymal chondrosarcoma, often affect adults ages 19 to 30^[4].

How doctors diagnose chondrosarcoma

A healthcare provider will ask about symptoms and do a physical exam. They may ask about signs and symptoms and examine the body to gather more clues about the diagnosis^[8].

Several imaging tests help doctors diagnose chondrosarcoma. X-rays provide the first look at the bones. CT scans (computed tomography) use X-rays to create detailed cross-sectional images and are particularly useful because they show the most characteristic findings for chondrosarcoma^[6]. MRI (magnetic resonance imaging) uses magnets and radio waves to create detailed pictures of soft tissues around bones^[8]. A bone scan and PET scan may also be ordered^[4][8].

A biopsy is needed to make a definitive diagnosis. During this procedure, a doctor removes a small sample of tissue from the suspicious lump or the entire lump^[4]. The tissue is sent to a laboratory where doctors who specialize in analyzing body tissues, called pathologists, examine it to determine whether it’s cancer^[8]. The definitive diagnosis depends on the identification of malignant cancer cells producing cartilage in the biopsy specimen^[6].

How the biopsy sample is collected depends on where the suspicious tissue is located. The procedure requires careful planning so that the biopsy is done in a way that won’t interfere with future surgery to remove the cancer^[8]. For this reason, it’s important to get a referral to a team of experts with experience in treating chondrosarcoma^[8].

If cells are cancerous, the pathologist will identify the tumor type and establish a tumor grade^[4]. A tumor grade is a measure of how fast a tumor may grow and spread. Chondrosarcoma grades range from 1 (I) to 3 (III)^[4]. Low-grade tumors grow slowly, while high-grade tumors grow and spread more quickly.

Treatment options

Chondrosarcoma treatment often involves surgery to remove the cancer. Other treatments might be recommended in certain situations. Which options are best depends on where the cancer is located, how quickly it’s growing, whether it has grown to involve other structures, overall health, and personal preferences^[8].

Surgery

Surgery is the main treatment for chondrosarcoma and the primary treatment for most types^[10][12]. The goal of surgery is to remove the cancer and a margin of healthy tissue around it^[8]. Complete, wide surgical excision of the chondrosarcoma is the preferred method when it is feasible^[12].

Wide resection removes the bone tumor and a small amount of tissue and bone around it. This is the most common surgical method used for chondrosarcoma, particularly for high-grade chondrosarcoma in the bones of the skull, spine, arms, legs, or pelvis^[10].

Limb-sparing surgery is often used to remove tumors in an arm or leg. During this procedure, surgeons remove the tumor without amputating the limb^[10]. Reconstructive surgery is done at the same time as surgery to remove the tumor. Bone and tissue grafts may be used to replace tissues removed during surgery. A joint removed with surgery may be replaced with a metallic artificial joint^[10].

Curettage is a procedure that uses a spoon-shaped tool with a sharp edge to scrape a tumor out of the bone. After curettage, the surgeon may use bone cement to fix the hole left in the bone and destroy any remaining cancer cells^[10]. This approach is used for low-grade tumors in the bones of the leg or arm.

Amputation removes all or part of the arm or leg with the tumor. It may be done when a chondrosarcoma has grown into the nerves or blood vessels, if the tumor is very big, or if the cancer comes back in the same area after limb-sparing surgery^[10]. Most people who have an amputation will use an artificial limb after surgery.

Radiation therapy

Radiation therapy uses high-energy rays or particles to destroy cancer cells^[10]. It plays a limited role in primary treatment but may be used in certain situations^[12]. Radiation therapy may be appropriate for the treatment of positive surgical margins or palliation of disease-related symptoms^[12]. It can also be offered when surgery isn’t possible or if the cancer comes back after surgery^[10].

Chemotherapy

Chemotherapy uses drugs to destroy cancer cells. Chondrosarcoma has not been shown to respond well to chemotherapy or radiation^[15]. However, chemotherapy plays a limited role and is sometimes offered for certain types^[12].

Mesenchymal chondrosarcoma may be treated with chemotherapy after surgery. The drug combinations used include combinations of vincristine, doxorubicin, cyclophosphamide, ifosfamide, etoposide, and dactinomycin^[10]. If this type has already spread at the time of diagnosis, different drug combinations may be used^[10].

Dedifferentiated chondrosarcoma may be treated with the same chemotherapy drug combinations that are used for osteosarcoma^[10]. Chemotherapy and radiotherapy may be used in dedifferentiated chondrosarcoma because distant spread may be present at the time of diagnosis, though surgery with clear margins remains the primary treatment^[12].

Outlook and survival

The outlook for people with chondrosarcoma varies depending on several factors, including the type of chondrosarcoma, its grade, where it’s located, and whether it has spread. Overall, 79% of people with chondrosarcoma are alive five years after diagnosis^[4].

Success depends on the stage of the disease, with low-grade tumors that haven’t spread offering the best outlook after complete surgical removal with clear margins^[12]. Most chondrosarcomas grow slowly and may not cause many signs and symptoms at first^[1]. Some rare types grow rapidly and have a high risk of spreading to other areas of the body, which can make these cancers difficult to treat^[1].

Chondrosarcomas in the arms and legs tend to have better outcomes with surgery than those occurring in the pelvis or spine, where complete removal can be more difficult^[12]. Regular follow-up is required to rule out local recurrences of chondrosarcoma and distant spread, which includes regular clinical evaluations and imaging^[12].