What are the other Names for this Condition? (Also known as/Synonyms)

• Jaw Osteogenic Sarcoma (JOS)
• Mandibular Osteosarcoma
• Osteogenic Sarcoma of Jaw Bones

What is Osteosarcoma of Jaw Bones? (Definition/Background Information)

• Osteosarcoma forms a class of highly-cancerous, high-mortality, bone tumor. After multiple myeloma, it is the second-most common primary tumor of the bones
• Osteosarcoma of Jaw Bones is a medullary type of osteosarcoma. They occur in the mandibles or maxillary bones (upper jaw, around the nasal cavity)
• The exact cause of the condition is unknown and presently, it is not possible to prevent Osteosarcoma of Jaw Bones occurrence
• A treatment of this bone tumor may involve surgery, chemotherapy, and radiation therapy. The prognosis of Jaw Osteosarcoma depends on the stage of cancer; higher grade osteosarcomas indicate a poorer prognosis

Osteosarcomas are classified in several different ways. They may be classified based on their cause/origin, location, or even based on certain diagnostic findings.

Based on where they occur, Osteosarcoma is classified as Medullary Osteosarcoma (occurring in the bone cavity) and Surface Osteosarcoma (occurring on the bone surface).

• Medullary Osteosarcomas are of several different types, and these include:
  • Conventional Osteosarcoma
  • Osteosarcoma of Jaw Bones
  • Post-Radiation Sarcoma
  • Osteosarcoma arising in Paget's Disease of Bone
  • Osteosarcoma in other Benign Conditions
  • Telangiectatic Osteosarcoma
  • Small Cell Osteosarcoma
  • Low-Grade Osteosarcoma
  • Multicentric Osteosarcoma
• Surface Osteosarcomas are of several different types, and these include:
  • Parosteal Osteosarcoma
  • Periosteal Osteosarcoma
  • High-Grade Surface Osteosarcoma

Who gets Osteosarcoma of Jaw Bones? (Age and Sex Distribution)

• Young and middle-aged adults (in the 3rd and 4th decade) are generally affected
• It has been observed that individuals with Osteosarcoma of Jaw Bones are usually 10 years older than those affected by conventional osteosarcoma (that generally affect the long bones)
• There is no known ethnic/racial preference; the condition is known to occur worldwide

What are the Risk Factors for Osteosarcoma of Jaw Bones? (Predisposing Factors)

The exact risk factors of Osteosarcoma of Jaw Bones are unknown. However, the risk of osteosarcoma (in general) is linked to following factors:

• Some genetic mutations are associated with osteosarcoma; including mutations in Rb gene and P53
• Individuals with bilateral retinoblastoma have a higher risk of developing the condition
• A few genetic disorders, such as Rothmund-Thompson syndrome, Bloom’s syndrome, Li-Fraumeni syndrome, hereditary multiple exostosis, and Werner syndrome, have been linked to the condition
• Paget’s disease of the bone, fibrous dysplasia, osteoblastoma, Ollier disease, and chemotherapy, are other conditions and disorders that are thought to be associated with osteosarcomas
• A previously performed radiotherapy for other cancer conditions - the tumor may be radiation-induced. The radiation has an expected side effect of damaging the genetic material in the normal cells. This can lead to the development of a “secondary” cancer
• Any physical injury or trauma

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Osteosarcoma of Jaw Bones? (Etiology)

• The exact cause and mechanism of Osteosarcoma of Jaw Bones formation, is unknown
• The tumor can occur due to some preexisting conditions and abnormalities (termed as a secondary osteosarcoma)
• Such preexisting conditions could include radiation-exposure, genetic anomalies, the presence of multiple chondroma, and any well-established physical injury or trauma
• A radiation-influenced tumor takes many years to develop, after the radiation exposure has ceased. This radiation may have been previously administered for treating other cancers

What are the Signs and Symptoms of Osteosarcoma of Jaw Bones?

Osteosarcoma of Jaw Bones signs and symptoms include:

• In the initial growing phase of the tumors, they are normally asymptomatic. The soft tissue tumors grow at a moderate rate, and then they suddenly start to rapidly progress
• Depending on the jaw bone that is affected, there may be pain, swelling, tenderness, displacement or bulging of teeth, tingling or pricking sensation (paresthesia), numbness
• Due to large size of the tumor, the adjoining organs, nerves, and muscles may be compressed or restricted
• The individual may have difficulty eating, swallowing, or breathing
• In some individuals, organ dysfunction and internal hemorrhages may be observed. These may be sudden and spontaneous developments

How is Osteosarcoma of Jaw Bones Diagnosed?

A diagnosis of Osteosarcoma of Jaw Bones is made using the following tools:

• Physical examination, evaluation of patient’s medical history
• Histopathological studies conducted on a biopsy specimen - the specimen is examined under a microscope by a pathologist, to arrive at a definitive diagnosis
• X-ray studies of the tumor
• MRI scan or CT scan of the affected area

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Osteosarcoma of Jaw Bones?

Complications of Osteosarcoma of Jaws are dependent on the site and severity of the tumor. These include:

• Due to obstruction of the nasal cavity or mouth, the individual may experience prolonged feeding and breathing difficulties
• The tumor mass may affect an individual’s appearance, their self-confidence, and self-esteem; thus, interfering with their regular school, work, or social life
• Reconstructive surgical procedures may be required, in order to restore profile of the face
• Damage of the following organs due to metastasis - liver, bones, and lungs
• Usually by the time osteosarcomas are detected, chances are that they would have proliferated and metastasized aggressively, damaging organs and tissues beyond repair
• They are known to have a high recurrence rate, even on surgical excision and removal
• Deep-seated tumors (those buried inside the body tissues) may cause damage to adjoining tissues and organs
• Blood loss during invasive treatment methods may be heavy
• Damage to vital nerves, blood vessels, and surrounding structures, during surgery
• Side effects from chemotherapy (such as toxicity), radiation therapy

How is Osteosarcoma of Jaw Bones Treated?

Treatment measures for Osteosarcoma of Jaw Bones include the following:

• Any combination of chemotherapy, radiation therapy, and invasive procedures, maybe used to treat the tumor
• Wide surgical excision of Jaw Osteosarcoma and removal of the entire lesion is the standard treatment mode. If the tumor is not fully removed, then it will recur
• After surgical removal of the tumor, reconstructive surgical procedures may be planned to correct facial defects and restore the face
• Embolization of the tumor is used to provide temporary relief from the symptoms, and reduce blood loss during a surgical procedure
• Post-operative care is important: A minimum activity level is to be ensured, until the surgical wound heals
• Follow-up care with regular screening and check-ups are important

How can Osteosarcoma of Jaw Bones be Prevented?

• Current medical research have not established a way of preventing Osteosarcoma of Jaw Bones occurrence
• However, the presence of any tumor or lesion should be immediately informed to the physician and periodic follow-up and screening maintained
• Regular medical screening at periodic intervals with blood tests, scans, and physical examinations, are mandatory for those who have already endured the tumor. This is due to both its high metastasizing potential and chances of recurrence. Often several years of active vigilance is necessary

What is the Prognosis of Osteosarcoma of Jaw Bones? (Outcomes/Resolutions)

• The prognosis of Osteosarcoma of Jaw Bones is better than that of conventional osteosarcoma

However, several prognostic markers are identified by research which helps determine the prognosis of Osteosarcoma of the Jaws (or Mandibular Osteosarcoma). Many of these prognostic markers are based upon defective genes or defective proteins found in the tumor. Some of these genetic defects that alter the prognosis are explained below.

The following conditions result in or indicate a poor prognosis:

• 13q14 loss of heterozygosity (gene loss) and mutations in Rb gene
• Presence of MDR-1 gene mutation, which is a multi-drug resistant gene, results in tumor not responding to certain chemotherapy agents
• The presence of c-FAS mutations in patients result in poorer prognosis, due to a poor response of the condition to chemotherapy and a higher chances of recurrent and metastatic osteosarcoma
• HER-2 over expression in tumor
• Loss of M-TAP gene

Other factors that are related to osteosarcoma prognosis include:

• Loss of heterozygosity of 18q in patients with Paget’s disease of the bone, has been shown to increase the development of osteosarcoma, in such patients
• Studies have shown that such tumors in children have the worst prognosis, compared to young adults with the tumor
• Some studies seem to indicate that men with these bone tumors have poorer prognosis, than women; but, this has not been substantiated
• Location of the tumor also determines its outcome; tumor in distal parts of the knee and elbow, have better outcomes, than those at other locations
• The size of the tumor also determines its prognosis; normally, larger tumors have much poorer prognosis than smaller-sized tumors
• Duration of symptoms are important factors too:
  • A shorter duration of symptoms lead to a worse prognosis
  • A longer duration of symptoms lead to a better prognosis
• A presence of spontaneous necrosis leads to the worst prognosis. Spontaneous necrosis means a type of necrosis that is present due to tumor growth and not due to treatment with chemotherapy

Additional and Relevant Useful Information for Osteosarcoma of Jaw Bones:

There are approximately 1000 cases of osteosarcomas, diagnosed each year in the United States.