What Is Osteosarcoma?
Here are several types of cells in our bones :
- Osteoblasts form the bone matrix (the connective tissue and minerals that give bone its strength).
- Osteoclasts prevent too much bone matrix from accumulating and help bones keep their proper shape. By depositing or removing minerals from the bones, osteoclasts help control the amount of these minerals in the blood.
- Bone marrow (found in some bones) contains fat cells and, most importantly, blood-forming cells. All blood cells (red blood cells, white blood cells, and platelets) are made in bone marrow.
There are 2 main types of bones flat bones and long bones. The flat bones help to protect the brain and the organs of the chest, abdomen, and pelvis. The skull bones and sternum (breast bone), for example, are flat bones. The long bones support the legs and arms. Muscles that move the arms and legs are attached to these long bones.
Osteosarcoma (also called osteogenic sarcoma) is the most common type of cancer that develops in bone. Like osteoblasts of normal bone, the cells that form this cancer produce bone matrix. However, the malignant bone tissue of an osteosarcoma is not as strong as that of normal bones.
Ewing tumor is the second most common malignant bone tumor in children and is described in a separate American Cancer Society document. Most other types of bone cancers are usually found in adults and are rare in children. These include chondrosarcoma (cancer that develops from cartilage) and malignant fibrous histiocytoma of bone.
Not all bone tumors are malignant. Cells that form benign tumors do not have the ability to spread to other parts of the body and are generally not dangerous. There are many types of benign bone tumors. These tumors are formed by different types of cells. Benign tumors formed by bone cells are osteomas. Benign tumors formed by cartilage cells are chondromas. Benign tumors with both bone and cartilage cells are osteochondromas. Other benign bone tumors of children and young adults include eosinophilic granuloma of bone, non-ossifying fibromas, xanthomas, giant cell tumors, and lymphangiomas.
Some benign bone tumors can be diagnosed by physical examination and how they look on x-rays. In other cases, a biopsy (taking a sample of tumor and examining it under the microscope) is needed to see whether the tumor is benign or malignant.
What causes osteosarcoma?
Most osteosarcomas develop in people who have no other diseases and no family history of bone cancer. Osteosarcoma may be triggered by an overactivity of bone cells. In a very small number of families, the siblings develop osteosarcoma. These families may be studied to see if a rare genetic defect may be causing the tumor. If such a defect is found, it may help doctors identify other family memebers that may be at risk and understand the process by which cancer develops in other patients with osteosarcoma.
Osteosarcoma is probably caused by a combination of genetic changes that together cause immature bone cells to become cancer cells instead of developing into bone. The same gene that is commonly abnormal in patients that develop eye tumors called retinoblastoma (the RB gene) may also be associated with osteosarcoma. The RB gene is a "tumor suppressor" gene that normally controls the growth of cells. When it becomes changed, or mutated, it can no longer control cell growth, and tumors can form. Defects in another tumor suppressor gene, P53, can also predispose individuals to osteosarcoma or other cancers. These gene disturbances are very rare.
What are the symptoms of osteosarcoma?
The symptoms of osteosarcoma can vary, depending on the bone in which the cancer develops. Symptoms may include:
- Pain in the bone or joint that gets worse over time
- A painless swelling or a noticeable mass in the arm or leg
- A broken bone that occurs without or with minimal injury or trauma
- Bone fracture (may occur after what seems like a routine movement)
- Limitation of motion
- Limping (if the tumor is in the leg)
- Pain when lifting (if the tumor is in the arm)
- Tenderness, or redness at the site of the tumor
- Stiffness or swelling of joints (uncommon)
- Back pain or loss of bowel or bladder control related to a tumor in the pelvis or at the base of the spine. This is very rarely the first sign that a child has osteosarcoma.
What are the prognostic factors in osteosarcoma?
Doctors use the following terms to describe osteosarcoma and develop treatment plans.
These factors include:
- Localized: The tumor is limited to the bone of origin and the tissue surrounding the tumor; it has not spread to other parts of the body.
- Metastatic: The tumor has spread from the bone where it began to other parts of the body; the most common sites of spread are the lungs or other bones.
- Recurrent: The tumor has come back after treatment. It can recur in the same place that it started, or in another part of the body. The lungs and other bones are the most common sites of recurrent tumors.
- Initial response to therapy: The other important prognostic (predictive of treatment success) factor is the patient's response to initial therapy. Patients whose tumor cells have nearly all been eliminated after the initial 10 weeks of chemotherapy have a better outlook than those whose tumor cells do not respond as well to treatment.
Exams and Tests
- Blood tests
- Bone scan to see if the cancer has spread to other bones
- CT scan of the chest to see if the cancer has spread to the lungs
- CT scan of the affected area
- Open biopsy (at time of surgery for diagnosis)
- X-ray of the affected area
Before major surgery to remove the tumor, chemotherapy is usually given. Chemotherapy is also used to kill or shrink any cancer cells that may have spread to other parts of the body.
Common chemotherapy medicines include:
- Carboplatin (Paraplatin)
- Cyclophosphamide (Cytoxan)
- Doxorubicin (Adriamycin)
- High-dose methotrexate with leucovorin
- Ifosfamide (Ifex)
For more information, medical assessment and medical quote
as email attachment to
Email : - firstname.lastname@example.org
Contact Center Tel. (+91) 9029304141 (10 am. To 8 pm. IST)
(Only for international patients seeking treatment in India)