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Orthopedic Oncology FAQs

General Tumor FAQs

What causes tumors?

In reality, nobody knows what causes a sarcoma or a benign bone tumor. Because of the rarity of these tumors it has been difficult to perform extensive research on these types of tumors. Most of these tumors are not inherited or past on. 

What is a tumor?

A tumor refers to an abnormal growth in the body. Tumors are made up of abnormal cells that are uncontrollably dividing and replicating themselves. Tumors can be classified as benign or malignant (cancerous). Depending upon the type of cell that the tumor is derived from, a malignant tumor can be classified as a sarcoma or a carcinoma. Some tumors may have genetic alterations that lead to development of the tumor. 

What are the differences between Sarcomas and Carcinomas?

Sarcomas and carcinomas are types of malignant tumors that can affect bones. They are derived from different types of cells. Sarcomas are derived from mesodermal (mesenchymal cells) and carcinomas are derived from epithelial types of cells. Sarcomas and carcinomas grow and spread differently.

Sarcomas grow like "ball-like" masses and tend to push adjacent structures like arteries, nerves, veins away.  Sarcomas usually involve the bone or soft tissues. 

Carcinomas grow in an infiltrative manner and grow through infiltration or invasion of adjacent structures. They more easily invade adjacent nerves, blood vessels and muscles. Carcinomas usually spread to bone and soft tissue from other sites (lung, liver, breast, etc.).

Is there a difference between “Bone Cancer” and “Bone Tumor?

These two terms are very general terms. A bone tumor refers to any abnormal growth from the bone or in the bone, benign or malignant. Bone cancer refers to a malignant bone tumor. It can be a primary malignant tumor like an osteosarcoma, Ewing's sarcoma or chondrosarcoma. It can also be a metastatic carcinoma such as a breast cancer, lung cancer, prostate cancer, kidney cancer and thyroid cancer. It is important to differentiate between the various types of cancers that affect the bone because each has its own type of treatment and prognosis.

Making a Diagnosis 

What is tumor “grade?”

Sarcomas are graded by pathologists. When the pathologist views a biopsy specimen or the final tumor under the microscope, he assigns a grade to the tumor. The grade is based on particular characteristics of the cells that compose the tumor. The grade reflects the degree of malignancy of the sarcoma and how fast it is growing. A high-grade tumor is a fast-growing tumor. High-grade tumors have a great potential to spread throughout the body (metastasis). 

What is a biopsy?

A biopsy is the act of obtaining a piece of tissue from a tumor. It is then studied under a microscope by a pathologist (a physician who specializes in this area) to determine the type of tumor. Determining the type of tumor, and whether it is benign or malignant (cancerous) enables the doctors to determine the type of treatment. It is essential to have a biopsy before any surgery or treatment is administered. 

What does “Staging” mean?

Staging is a way of assessing specific characteristics about a sarcoma and correlating it with a prognosis. It is a way of estimating a prognosis for patients. Staging studies are used to determine if a tumor has spread to another site, which may alter the prognosis. 

Questions About Treatment

How does chemotherapy work?

Chemotherapy is the administration of certain toxic drugs in an attempt to kill cancer cells and cure patients of their cancer, shrink tumors to facilitate surgical resection or prolong a patient's life. Chemotherapy is typically administered for high grade bone sarcomas. It is usually given before surgery (preoperative chemotherapy=neoadjuvant chemotherapy=induction chemotherapy) to try to kill the tumor before taking it out. 

What is a Percutaneous Radiofrequency Ablation (RFA)?

The latest, "State of the Art Treatment" for Osteoid Osteoma is  Percutaneous Radiofrequency Ablation (RFA). This is a minimally invasive procedure that is performed under a CAT Scan, usually by a highly specialized musculoskeletal radiologist, in which a needle or probe is inserted into the lesion and the lesion is heated and destroyed. The CAT scan is utilized to localize the Osteoid Osteoma so the needle can be guided directly into the tumor. It is an outpatient procedure. The patient goes home the same day. It is minimally invasive and therefore only a small stab incision or poke hole is made for the needle. 

Questions about Surgery

What is limb sparing surgery?

A limb sparing surgery is also called a resection. Resections are usually performed for malignant tumors and very large benign aggressive tumors that have destroyed almost the entire bone. A radical resection is typically performed for high grade tumors. Limb sparing surgery can be performed for approximately 95% of malignant bone tumors. With a resection, the tumor is removed with the bone (or part of the bone) and usually the adjacent joint. The bone and joint must be restored. This part of the procedure is called a reconstruction. Usually a metal prosthesis (replica of the bone and joint) is used to restore (reconstruct) the bony and joint deficiency. Limb sparing surgery can also be performed for soft tissue sarcomas. This usually does not involve removal of bone or placement of a prothesis. It usually incorporates radiation in the treatment plan in order to kill any microscopic tumor cells in order to make it easier to remove the tumor and save the surrounding soft tissue. Limb sparing surgery of soft tissue sarcomas or bone sarcomas may require muscle flaps to fix the soft tissue, prevent infection and enable the arm or leg to function.