What is Chondrosarcoma?
Chondrosarcoma is a cancer composed of cells derived from transformed cells that produce cartilage. Chondrosarcoma is a member of a category of tumors of bone and soft tissue known as sarcomas. About 30% of skeletal system cancers are chondrosarcomas. It is resistant to chemotherapy and radiotherapy. Unlike other primary bone cancers that mainly affect children and adolescents, chondrosarcoma can present at any age. It more often affects the axial skeleton than the appendicular skeleton. The cause is unknown. Patients may have a history of enchondroma or osteochondroma. A small minority of secondary chondrosarcomas occur in patients with Maffucci syndrome and Ollier disease.
Imaging studies - including radiographs ("x-rays"), computerized tomography (CT), and magnetic resonance imaging (MRI) - are often used to make a presumptive diagnosis of chondrosarcoma. However, a definitive diagnosis depends on the identification of malignant cancer cells producing cartilage in a biopsy specimen that has been examined by a pathologist. In a few cases, usually of highly anaplastic tumors, immunohistochemistry (IHC) is required. There are no blood tests currently available to enable an oncologist to render a diagnosis of chondrosarcoma. The most characteristic imaging findings are usually obtained with CT.
Treatment depends on the location of the disease and the aggressiveness of the tumors. Because chondrosarcomas are rare, they are treated at specialist hospitals with Sarcoma Centers. Surgery is the main form of treatment for chondrosarcoma. Musculoskeletal tumor specialists or orthopedic oncologists are usually chosen to treat chondrosarcoma, unless it is located in the skull, spine, or chest cavity, in which case, a neurosurgeon or thoracic surgeon experienced with sarcomas is chosen. Often, a limb-sparing operation can be performed, but in some cases amputation is unavoidable. Amputation of the arm, leg, jaw, or half of the pelvis (called a hemipelvectomy) may be necessary in some cases. Chemotherapy or traditional radiotherapy are not very effective for most chondrosarcomas, although proton therapy is showing promise with local tumor control at over 80%.
Prognosis depends on how early the cancer is discovered and treated. For the least aggressive grade, about 90% of patients survive more than five years after diagnosis. People usually have a good survival rate at the low grade volume of cancer. For the most aggressive grade, only 10% of patients will survive one year. Tumors may recur in the future. Follow up scans are extremely important for chondrosarcoma to make sure there has been no recurrence or metastasis, which usually occurs in the lungs.
Treatment of sarcoma, especially when the sarcoma has spread, or "metastasized", often requires chemotherapy but existing chemotherapeutic medicines are associated with significant toxicities and are not highly effective in killing cancer cells. Therefore, research to identify new medications to treat sarcoma is bing conducted as of 2019. One possibility is the use of cancer immunotherapy (e.g., immune checkpoint inhibitors like anti-PD1, anti-PDL1, and anti-CTLA4 agents) to treat sarcomas.
Journal of Clinical Oncology and Cancer Research,