Osteoarcoma

Osteosarcoma Cancer now is one of major problems that trouble human. is different from normal cell growth. Instead of dying, cancer cells continue to grow and form new, abnormal cells. Cancer cells can also invade (grow into) other tissues, something that normal cells cannot do. Growing out of control and invading other tissues are what makes a cell a cancer cell .Topic of my essay is about bone cancer.I decide to write this in topic because it involved elderly people that I they’re suffering from this disease. Make me interest in this disease. From now I show you what is osteosarcoma, symptom, diagnosis,Its cause and the possible ways to treat Osteosarcoma is also known as osteogenic sarcoma. Sarcoma is a type of cancer that starts in the cells of the soft tissues or bone. Most of this disease are serious type (high-grade malignancy) rarely to find low-grade types in children. This disease is a malignant neoplasm of bone. It is among the most common non hematologic primary malignant tumors of bone in both children and adults. The conventional type arises in the intramedullary cavity of the bone and represents 75 % of all osteosarcomas.These tumors penetrate and destroy the cortex of the bone and extend into surrounding soft tissues From embryonic cells mesenchymal stem cells grow as a malignant osteoid tissue that it spread to surrounding tissues quickly. And spread through the bloodstream. Makes the prognosis worse when 20 years ago, patients with no spread of the disease and surgery, then took out a tumor recurrence and were bornmore than 80% of patients die within 5 years  Osteosarcoma develops in the osteoblast cells that cover the bone. It usually starts in ends of the long bones around the knee, where new tissue forms as children grow. However, osteosarcoma can also start in the upper leg, lower leg, upper arm bone, pelvis, shoulder, and skull. When cancer spreads from its original place to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the original tumor. For example, if osteosarcoma spreads to the lungs (metastases), the cancer cells in the lungs are osteosarcoma cells. The disease is metastatic osteosarcoma, not lung cancer, and it is treated as osteosarcoma. (1)&(2) Simple picture to show how osteosarcoma is looks like. And the position of tumor. Symptom of Osteosarcoma Many patients first complain of pain that may be worse at night, and may have been occurring for some time. If the tumor is large, it can appear as a swelling. The affected bone is not as strong as normal bones and may fracture with minor trauma (a pathological fracture)Suffer may have this following symptom : * Bone fracture (may occur after what seems like a routine movement) * Bone pain * Limitation of motion * Limping (if the tumor is in the leg) * Pain when lifting (if the tumor is in the arm) * Tenderness, swelling, or redness at the site of the tumor Cause of Osteosarcoma According by the present information Scientists have identified some genetic mutations that cause some inherited forms of osteosarcoma. Specifically, people with the Li-Fraumeni syndrome have a high risk of developing certain kinds of cancer, including osteosarcoma. This disease is caused by inherited mutations that turn off the p53 tumor suppressor gene that normally controls the growth of cells.However the cause is still unclear. People with inherited defects in the retinoblastoma (Rb) tumor suppressor gene also have a higher risk of developing retinoblastoma, an eye cancer, and osteosarcoma. When the Rb gene is mutated, or changed, it can no longer control cell growth and tumors form as a result. Here are the list of involved gene information RB - It is known that patients affected by hereditary RB have 1000 times the incidence of osteosarcoma compared with the general population. Sporadic osteosarcomas show alteration of the RB gene in 70 % of cases. - Loss of heterozygosity (LOH) at 13q, the site of gene RB is present in approximately 60 % to 70 % of osteosarcomas. And recently LOH at the RB locus has been proposed as a poor prognostic factor in osteosarcoma. - Abnormalities of the RB gene are commonly seen in osteosarcoma but other components of the RB-pathway gene can be subject to genetics alterations : INK4, p16, CDK4 and cyclin D1. The INK4A gene located on chromosome 9p21 is inactivated in about 10 % of osteosarcomas. Loss of p16 expression is also found in 10 % to 15 % of tumors and is correlated with decreased survival in pediatric osteosarcomas. - Amplification of the 12 q13-15 chromosomal region which contains both CDK4 and MDM2 is seen in about 10% of osteosarcomas. P53 - Inactivation of the p53 pathway is central event in many tumors including osteosarcoma. The p53 gene is located on chromosome 17p13, chromosomal region frequently altered in cytogenetic analysis. Abnormalities of p53 were identified in 50 % of cases. p53 mutations are more often missense type. Alterations of p53 observed in osteosarcoma can be allelic loss or gene rearrangements (10-20 %) or point mutations (20-30 %). In patients with the Li-Fraumeni syndrome who have a germline mutation of p53 they are a high risk of osteosarcoma. And in 3 % of patients with sporadic osteosarcoma, germline mutations in p53 are identified.  Some genes are involved in the regulation of p53 and abnormalities of these are detected in cases of osteosarcoma. - The MDM2 gene located on chromosome 12q13 encodes a protein that negatively modulates p53 function by binding the p53 protein. MDM2 is amplified in 5-10 % of osteosarcomas. - Another important protein is the p14 product of the INK4 gene. The p14 protein exerts a protective effect on p53. For some authors either or two singular events : INK4A deletion or 12q13 amplification can inactivate two separate pathways of cell cycle control. But direct genetic alteration of both p53 and RB do not co-exist with either INK4A deletion or 12q13 amplification. So, three pathways of cell are possible to induction of an osteosarcoma. Most osteosarcomas are not caused by inherited genetic mutations. Rather, they are a result of mutations acquired during a person's lifetime. People with these mutations do not pass them on to their children. Radiation treatment is one of the known causes of genetic mutations that can trigger osteosarcoma. For this reason, bones exposed to radiation to treat another cancer are more likely to develop osteosarcoma in the bone that was treated. (3)the process how tumor growth on bone and bone marrow Diagnosis of Osteosarcoma In addition to a physical examination, the following tests may be used to diagnose osteosarcoma. It is recommended that specialist with experience diagnosing and treating bone tumors perform these tests. The following proceed below is how to diagnosis. X-ray.  take an x-ray of the area where there is a lumep or swelling. Osteosarcoma usually shows certain common features on an x-ray. Computed tomography (CT or CAT) scan.  Magnetic resonance imaging (MRI).  Bone scan. A bone scan uses a radioactive tracer to look atthe inside of the bones. The tracer is injected into a patient’s vein. Arteriogram (also called angiogram). A doctor injects a small amount of a contrast medium that can be detected by x-ray into an artery. A surgeon may use this test to help plan surgery. Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Treatment Because of osteosarcoma is hardly respond to radiation therapy (or radioresistant) So how is the main treatment consists of surgery, remove the tumors. And chemotherapy (adjuvant chemotherapy) to remove cancer that has spread. (Micrometastasis).here are the main proceed to treat this disease. 1. SURGERY. Surgery is the main method of treatment of bone cancer is divided into two approaches together is entire rod out of surgery (amputation) or cut out all specific tumors. The finest pieces stuck around with the output (limb salvage) surgery need to consider how to select the various factors involved. 2. RADIOTHERAPY. Osteosarcoma classified as their radioresistant. The use of radiation lower than 6,000 cGy to control cancer evil short only Even so, radiation high 8,000 cGy was also cancer still survive, so the radiation therapy with chemotherapy to reduce the size oftumors and then following the surgery. Or use the help of surgery, radiation therapy in patients with surgically removed, not all. Or bone tumors around the central trunk (axial skeleton tumors) and so on. 3. CHEMOTHERAPY. Period before treatment with osteosarcoma amputation is the only way is to make more than 80% of patients had cancer spread generally within 6-9 months. And often died for all during the last 20 years when it was found that doxorubicin (adriamycin) and high-dose methotrexate (HDMTX) + leucovorin rescue to be successful in the treatment of patients with cancer metastases. By all of information that I shown to you, Osteosarcoma is one of disease that we should beware because the main cause come from our lifestyle, environment to change genetic express so hope that my information can help someone to make their decision and due to patient who affect this disease would be treated done in not many day. References: (1) Osteosarcoma, American Cancer Society Cancer Facts & Figures 2010. Atlanta, Ga. American Cancer Society 2010. (2) http://en.wikipedia.org/wiki/Osteosarcoma (3) Oncologist-approved cancer information from the American Society of Clinical Oncology, Cancer.Net Editorial Board,  07/10(last update 30 August 2010) (4) http://atlasgeneticsoncology.org/Tumors/OsteosarcID5043.html,Atlas of Genetics and Cytogenetics in Oncology and Haematology (5) http://www.gwunyeechin.com/osteosarcoma-process.html,Gwun-Yee Chin medical art& interactive media