Symptoms of osteosarcoma are dependent on the location of the tumor [7]. However, some of the most common presentations include limitation of motion of joints, limping, redness, swelling, bone fractures, bone pain following any form of movement or exertions on the extremities.

The pain experienced varies from one patient to the other. Some stop feeling pains when the joint is at rest while for others, the pains continue even when fully at rest leading to sleep deprivation in some cases. When any of these presentations are visible the muscle in the affected limb will feel smaller than those in the opposite limb.

There are different medical procedures that aid in the diagnosis of osteosarcoma [8]. Physical examination is needed to establish swelling and redness. Medical history is vital to see previous illnesses and medical treatments that may suggest the presence of an etiologic factor. A blood test may be used to check for the presence of tumors. Other tests that can be carried out include a CT scan, MRI, X-ray, PET scan, biopsy and bone scan. All of these will demonstrate the presence of osteosarcoma.

Generally, osteosarcoma is treated with the aid of a combination of therapies [9]. This can include chemotherapy, radiation therapy and surgery. Before surgery, patients with high grade tumors are subjected to neo-adjuvant therapy.

Surgery involves the removal of tumor with a wide margin. The goal of this is to leave the area free of all disease.

Majority of tumors at the bones and joints can now be removed safely without losing the limb affected. To replace tissues removed during the surgery, a surgeon can use a metal implant, an allograft a combination of both or bone removed healthy areas of the body.

After a successful surgery, a pathologist should examine the necrosis rate of the osteosarcoma [10]. It is the indicator of how well the tumor is responding to chemotherapy. Drugs are chosen for additional chemotherapy treatment based on this necrosis rate. This additional chemotherapy lasts six months on average.

When the disease is localised and metastasis hasn’t ensued, there is a long term survival rate of 70 to 75% [6]. However as soon as metastasis sets in, prognosis is negative and survival rate drops to 30% especially if the metastasis affects the lungs.

There have been many studies aimed at the etiologic factor responsible for osteosarcoma. However, it is still unclear, what actually leads to osteosarcoma. An etiologic factor is only seen in around 15% of cases [3].

Some of the etiologic factors that have been identified till date include:

• Radiotherapy: Radiation treatment for cancer can lead to a damage of the DNA in bone cells. 
• Underlying bone abnormalities: One good example of a disorder that can lead to the development of osteosarcoma is Paget disease. 
• Genetic factors: Genes for osteosarcoma can be inherited from a parent and this increases the possibility of the condition developing. 

Osteosarcoma is among the top 8 forms of childhood cancer. It makes up 2.4% of all malignancies in pediatric patients and around 20% of all cases of primary bone cancers [4]. In the United States, the incidence of the condition in patients aged 20 and below is placed at 5.0 cases per million each year in a general population. However the incidence varies slightly when ethnicity is considered. In blacks, incidence is 6.8/million, in Hispanics it is 6.5/million and in white ethnicities it is 4.6 per million each year.

The condition is seen more in males than in females with incidence placed at 5.4 per million and 4.0 per million respectively.
It originates more frequently in the metaphyseal region of tubular long bones. 42% of cases is seen in the femur, 19% is seen in the tibia and 10% in the humerus. Around 8% of all cases happen in the skull and jaw and another 8% is seen in the pelvis.

Osteosarcoma arises when there is a malignant growth of the bone cells that are responsible for the production of the hard boney matrix [5]. This malignant growth is what forces the cell to grow into a cancerous tissue or tumor. The bone cells that are seen in the tumor retain their bone like functions by growth and division. This explains how they are able to spread to other areas of the body.

Osteosarcoma cannot be prevented.

Osteosarcoma is the most common type of bone cancer [1]. It is seen mostly in children and teenagers as it generally involves the long bones near metaphyseal growth plates. It is possible for older adults to develop this condition but the vast majority of patients are aged 6 to 25. Teenagers develop this type of bone cancer the most and males develop it more than females. This phenomenon may be as a result of the fact that bones grow at a very fast rate for boys.

The cancer often develops in the bones of the legs and arms but most cases of it originate around the ends of the long bones which make up the knee [2]. When left untreated, osteosarcoma can spread to virtually any part of the body. The lungs and other bones are the most common metastasis sites for osteosarcoma.

Osteosarcoma is a cancer of the bone. It is mostly seen in the long bone in the legs in people younger than 20 years of age. However, it can arise in just about any bone in any part of the body. The cancer, if left untreated can spread to other organs of the body.

The chances of recovery from this type of cancer are high as long as the condition gets discovered early enough. Treatment is by surgery and use of chemotherapy primarily.

1. Marulanda GA, Henderson ER, Johnson DA, Letson GD, Cheong D. Orthopedic surgery options for the treatment of primary osteosarcoma. Cancer Control. Jan 2008;15(1):13-20. 
2. Vander Griend RA. Osteosarcoma and its variants. Orthop Clin North Am. Jul 1996;27(3):575-81.
3. Ottaviani G, Jaffe N. (2009). The epidemiology of osteosarcoma. In: Jaffe N. et al. "Pediatric and Adolescent Osteosarcoma". New York: Springer.
4. Kim SY, Helman LJ. Strategies to Explore New Approaches in the Investigation and Treatment of Osteosarcoma. Cancer Treat Res. 2010;152:517-528.
5. Peltier LF. Tumors of bone and soft tissues. Orthopedics: A History and Iconography. San Francisco, Calif: Norman Publishing; 1993:264-91.
6. Rutkow IM. The nineteenth century. Surgery: An Illustrated History. St Louis, Mo: Mosby-Year Book; 1993:321-504.
7. Mallon WJ. The registry of bone sarcoma. Ernest Amory Codman: The End Result of a Life in Medicine. Philadelphia, Pa: WB Saunders Co; 2000:107-21.
8. Osuna D, de Alava E. Molecular pathology of sarcomas. Rev Recent Clin Trials 4 2009 (1): 12–26. 
9. Dhaliwal J, Sumathi VP and Grimer RJ. Radiation-induced periosteal osteosarcoma. Grand Rounds 10: 13-18.
10. Papalas JA, Balmer NN, Wallace C, Sangüeza OP. Ossifying dermatofibroma with osteoclast-like giant cells: report of a case and literature review. Am J Dermatopathol 2009 31 (4): 379–83.