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

• High-Grade Surface Osteogenic Sarcoma

What is High-Grade Surface Osteosarcoma? (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
• High-Grade Surface Osteosarcoma is a type of surface osteosarcoma (one that is present on the surface of the bone). It is the most infrequent type of surface osteosarcoma
• The long bones of the body (typically the thigh bones) are most commonly affected by this malignant tumor
• The exact cause of the condition is unknown and presently, it is not possible to prevent High-Grade Surface Osteosarcoma occurrence
• A treatment of this bone tumor may involve surgery, chemotherapy, and radiation therapy. The prognosis of High-Grade Surface 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 High-Grade Surface Osteosarcoma? (Age and Sex Distribution)

• High-Grade Surface Osteosarcomas have a male predominance; the tumor usually occurring in the 2nd or 3rd decade of life (children and young adults of ages 10-29 years)
• There is no known ethnic/racial preference; the condition is known to occur worldwide

What are the Risk Factors for High-Grade Surface Osteosarcoma? (Predisposing Factors)

The risk of osteosarcoma is linked to the 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 High-Grade Surface Osteosarcoma? (Etiology)

• The exact cause and mechanism of High-Grade Surface Osteosarcoma formation, is unknown
• The tumor can occur de novo or spontaneously (termed as a primary osteosarcoma), or 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 High-Grade Surface Osteosarcoma?

The presentations are based on the location of the tumor. High-Grade Surface Osteosarcoma signs and symptoms include:

• Presence of a mass, with or without pain
• 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
• Due to large size of the tumor, the adjoining organs, nerves, and muscles may be compressed or restricted. Often, these signs along with pain, swelling, and tenderness, are the first indications of High-Grade Surface Osteosarcoma
• In some individuals, organ dysfunction and internal hemorrhages may be observed. These may be sudden and spontaneous developments
• Lesions beneath the skin (in rare cases), may appear as painful inflammations
• Frequently, the thigh bone is affected (around its midpoint); though other long bones (like the shinbone) may present with this condition

How is High-Grade Surface Osteosarcoma Diagnosed?

A diagnosis of High-Grade Surface Osteosarcoma 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. On tissue biopsy, these tumors show very high-grade cytological features
• 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 High-Grade Surface Osteosarcoma?

Complications of High-Grade Surface Osteosarcoma are dependent on the site and severity of the tumor. These include:

• 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 High-Grade Surface Osteosarcoma Treated?

Treatment measures for High-Grade Surface Osteosarcoma include the following:

• Any combination of chemotherapy, radiation therapy, and invasive procedures, maybe used to treat the tumor
• Wide surgical excision of High-Grade Surface Osteosarcoma and removal of the entire lesion is the standard treatment mode. If the tumor is not fully removed, then it will recur
• Embolization of the tumor is used to provide temporary relief from the symptoms, and reduce blood loss during a surgical procedure
• When the tumor is at an inaccessible location, or is unsafe for surgical intervention, non-invasive procedures are adopted
• 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 High-Grade Surface Osteosarcoma be Prevented?

• Current medical research have not established a way of preventing High Grade Surface Osteosarcoma 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 High-Grade Surface Osteosarcoma? (Outcomes/Resolutions)

• Currently, no specific prognosis of High-Grade Surface Osteosarcoma is available, which is a very rare kind of tumor

However, several prognostic markers are identified by research which helps determine the prognosis of High-Grade Surface 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
• In general, patients with primary osteosarcoma have better prognosis than those with secondary osteosarcoma

Additional and Relevant Useful Information for High-Grade Surface Osteosarcoma:

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