What is a chondrosarcoma?

Chondrosarcomas are cartilaginous cancer tumors and consist of abnormal bone and cartilage growth. These are the second most common primary bone tumor and tend to progress slowly. Primary chondrosarcomas typically develop from previously normal bone tissue, while secondary tumor volumes arise from benign enchondromas or osteochondromas.

There are several different types of chondrosarcomas, with distinctions based on the type of cells identified when they are examined under a microscope.

Only five to ten percent of these tumors are considered high grade tumors with a high metastatic rate and poor prognosis. The majority of chondrosarcomas arises in the medullar cavity, but may present in the bones of the arms, legs, ribs, pelvis, hands and feet. In extremely rare cases, chondrosarcomas may present in internal organs. Should the disease spread outside of the primary tumor, it is most likely to develop in the lungs. Though metastasis is rare among low-grade tumors, nearly all high-grade tumors will metastasize.

Who gets chondrosarcomas?

These tumors are most commonly found in adults in their late 20s to 60 years of age, who have been exposed to previous radiation therapy or chemotherapy. Some scientists believe the tumors are the end result of a hereditary predisposition. Conditions such as Ollier disease, Maffuci syndrome, Exostoses, and Wilms’ tumor are currently thought to increase the risk for developing a chondrosarcoma, although most chondrosarcoma patients are free of these conditions. Some studies show a connection in adult chondrosarcoma patients and a condition known as Paget’s disease. Recent studies in genetics show specific gene locations which may be linked to the development of chondrosarcomas; however more research is required for a definitive answer.

What are the symptoms of a chondrosarcoma?

The symptoms associated with chondrosarcomas vary greatly because they have the potential to grow in a wide variety of locations. An individual suffering from a chondrosarcoma may experience diplopia (double vision) due to cranial nerve palsies, headaches, loss in hearing, dizziness, tinnitus, pain, swelling, facial sensory abnormality, changes in gait, decreased range of motion around affected area, etc. Most chondrosarcoma patients will not experience pain that is a direct result of the tumor. However, many will experience pain and/or discomfort in the vicinity of the tumor.

What are the methods for detecting chondrosarcoma?

After completing a series of questions, a physician will typically order a plain X-ray to evaluate the area of concern for the patient. Since a benign lesion and a low grade tumor will appear relatively similar on a plain X-ray, the physician will likely order a more in-depth study of the mass using an instrument called a Bone Scan. In addition to a Bone Scan, your physician may order a Computed Tomography Scan, and/or a Magnetic Resonance Scan to further assist is the diagnosis, staging and treatment planning of a chondrosarcoma.

What are the treatment options for chondrosarcomas?

The primary treatment option for chondrosarcoma is surgery, with a goal of complete resection. In some cases, this may require amputation of the affected limb, however in base-of-skull or pelvis patients, this option is not feasible. If the tumor cannot be completely removed, most patients experience a recurrence within 2 to 3 years, and metastatic disease will develop in 10% of those patients. Radiation therapy is typically give post-operatively and works well for local control where complete resection was not possible or for palliative care.

Proton therapy is a successful treatment option that offers the flexibility of delivering high treatment doses to the tumor, while limiting doses to surrounding healthy tissues of critical nature such as the brain stem and spinal cord.

A major consideration for treatment of chondrosarcomas is the patient's quality of life during and following treatment. With proton therapy, the reduced radiation exposure to healthy tissues and critical structures translates to significant improvements in the daily life of the patient and a reduced risk of neurocognitive side effects.

What is the prognosis?

As is true with most malignant diseases, the prognosis or outcome depends on many different factors. These factors may include age, gender, overall patient health, complicating health issues (diabetes, lupus etc.), as well as the grade of the tumor volume. For chondrosarcoma, a primary determinate for prognosis is the combination of tumor grade and a successful surgical resection of the tumor volume. For lower grade tumors, the prognosis tends to be very good, however higher grade lesions have a uniformly poor prognosis.

• Grade I (or “low grade”) tumors most resemble normal cartilage, but may surround areas of lamellar bone (which is not seen in benign lesions), or show atypical cells including binucleate forms (cells with two nuclei instead of one).
• Grade II (or “intermediate grade”) are more cellular with a greater degree of nuclear atypia, hyperchromasia and nuclear size (Schiller, 1985).
• Grade III (or “high grade”) tumors have significant areas of marked pleomorphism, large cells with more hyperchromatic nuclei than grade II, occasional giant cells and abundant necrosis. Mitoses are frequently detected.

*Grade descriptions courtesy of http://sarcomahelp.org

Prognosis by Tumor Grade
	Five-Year Survival	Metastatic Potential	Recurrence Rate
Grade I	90%	0%	Low
Grade II	81%	10-15%	moderate?
Grade III	29%	>50%	High
Dedifferentiated	<10% (1 year)	Most	High

Chondrosarcoma: Diagnosis, Treatment and Prognosis