What is osteosarcoma?
Osteosarcoma or Osteogenic sarcoma is a type of cancer which begins in bones. Osteosarcoma is the eighth most common cancer of the bone in adolescent and children and males are more affected than females. Usually, teenagers are most commonly affected but it can also occur in adults. Osteosarcomas can affect any bone, however there are more incidences in legs, arms and especially near joint areas and in areas where the bone grows quickly (near the end of long bones).
Osteosarcomas can affect any bone. However, there are more incidences in legs, arms and especially near joint areas and in areas where the bone grows quickly (near the end of long bones).Most common location for development of Osteosarcoma is around the knee (lower part of thigh bone or in the upper part of shin bone)
Osteosarcomas can present with painful symptoms.
Osteosarcomas are classified on the basis of their appearance on X-ray and pathology . They are defined as low grade, intermediate grade and high grade. Grading shows the potential of the tumour to spread.
Causes and risk factors
The exact cause of osteosarcoma is not clear. Osteosarcomas may result due to exposure to radiation or certain genetic disorders and changes in the genes.
Risk factors for developing Osteosarcoma includes:
- Age- Risk of Osteosarcoma is more in teenagers suggesting a link between increase bone growth during this period and tumour formation. In middle age the risk declines and then again in older adults (>60 years), the risk rises. In older adults, Osteosarcoma is attributed to long-standing bone diseases.
- Gender and height- Male are more commonly affected, and usually, children who have Osteosarcoma are tall.
- Radiation- People who have had radiation therapy for other cancers are more at risk for developing Osteosarcoma
- Bone diseases- Osteosarcoma occurs more commonly in people with
- Paget disease of bone- There is formation of abnormal bone tissues and bone become weak, and they can fracture
- Hereditary multiple osteochondromas- These are benign cancers formed by bones and cartilage and can develop into Osteosarcomas
- Inherited cancer syndromes- People with Li-Fraumeni syndrome (due mutation in genes) are at risk of developing osteosarcoma
Symptoms and signs
- Pain – Most common symptom is Pain around the knee or in the upper arm. Pain is intermittent increases with activity, is worse at night. Patients may develop a limp due to pain
- Swelling- After several weeks of pain, swelling starts. A lump or mass is felt
- Fracture of Bone- Normally fracture of the bone is not seen in Osteosarcoma. In people with Osteosarcoma, the bones become weak and then fractures occur.
Typically osteosarcomas as detected when an individual notices certain symptoms and signs. On suspecting tumours in the bone, certain tests and procedures would be carried out to diagnose osteosarcoma.
The doctor will look at the complete medical history and do a physical examination for possible tumours and other diseases. In adults often osteosarcoma is a result of cancer in other parts of the body.
Diagnostic scans for locating the site of the tumour spread reoccurrence and to know if the treatment is working or not may be performed. This include:
- X-rays of bones: This is often the most preferred test to detect tumours of the bones. Further tests via biopsy may be needed to confirm osteosarcoma.
- Magnetic resonance imaging (MRI) scan: These are used to generate meticulous images of the soft tissues and bone structures of the body
- Computed tomography (CT) scan: Here x-rays are utilised for creation of cross-sectional images of the intended part of the body. On finding tumours, CT scans are used to see the tumour’s progression into adjoining areas.
- Bone scan: It is done to detect if cancer has spread to other bones as well.
- Positron Emission Tomography (PET) scan: Low levels of a radioactive preparation is injected which reaches cancerous regions and detects uptake of glucose. Cancer cells utilise glucose unusually than the normal tissues.
Imaging procedures may show up the bone tumours but biopsy is used to ascertain them. The biopsy is performed usually under local anaesthesia and may be either needle or surgical biopsy.
Treatment and prevention
Osteosarcoma treatment depends upon the location and size of the sarcoma, grade and if it has spread to other areas and the individual’s general state of health.
Staging of Osteosarcoma
Staging detects the spread of cancer. Treatment depends on staging. Simple system of staging are used- Localized (tumour is limited to an area) and metastasized (tumour has spread to other parts of the body)
In many cases, people with osteosarcoma may require a mix of surgery, radiotherapy and chemotherapy. Surgery is done for removal of the tumours in the bones. Radiotherapy is done when surgery is not feasible.
The affected region is excised surgically along with a bit of the surrounding healthy tissue. The replacement of the bone is done with a bone from another part or by placing a prosthesis. In case the osteosarcoma has spread to blood vessels and nerves, it may require amputation.
Drugs are used to kill the cancer cells. It is often used in individuals with osteosarcoma. Chemotherapy is widely used and before surgery, it is meant for shrinking the tumour.
Chemotherapy can have certain side-effects which may be managed by use of other medication.
- Radiotherapy: High-energy beams are used to kill the cancer cells here.
Certain lifestyle changes are known to reduce the risk of several cancers in adults but there are no ways reported for preventing osteosarcoma at present.
- Pathological fractures
- Side effects from Chemotherapy- Anemia, Nausea & Vomiting, Hair loss, Bone marrow damage, increased susceptibility to infections
- Side effects from Radiotherapy- Fatigue, Nausea & Vomiting, Hair loss, Infertility, Weight Loss
Consult your doctor on noticing pain or swelling not responding to medications. Consult your physician about any questions and concerns which you might have about the diagnosis and treatment options in case osteosarcoma is diagnosed.
Osteosarcoma often can progress rapidly. Individuals with pain for less than a year or swellings in and around the knee or in the arm that has been increasing must visit their doctor immediately, for it could be a risk factor for osteosarcoma.
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