Scientists have found several risk factors that make a person more likely to develop sarcomas.
A gene is the basic physical unit of heredity, a linear sequence of nucleotides along a segment of DNA that provides instructions for synthesis of proteins that perform and regulate all cell and thus body functions. A mutation is an alteration in the normal DNA structure or sequence of a gene. They may be beneficial, may have no affect, or may be deleterious to the cell. However, many diseases, sarcoma among them, begin with mutations in genes important in cell cycle regulation. These genetic errors can be acquired randomly as a result of a mistake during normal cellular division or due to environmental factors, such as exposure to certain toxic chemicals.
There are a few known genetic mutations that are frequently associated with certain types of sarcoma. For example, Ewings’s Family of tumors are all characterized by a chromosomal translocation, meaning a small piece of one chromosome switches places with a small piece of another chromosome. For instance, some of what belongs (genes for example) on chromosome number 11 may be found on number 22, and some of what should be on number 22 may be found on number 11. Another example is found in patients with GIST. It is now known that the majority of patients diagnosed with this subtype express a specific gene mutation that “turns on” a gene containing instructions for controlling when cells grow and divide (called an oncogene). More specifically, GIST expresses a mutation for a receptor protein tyrosine kinase, causing this specific oncogene to become overactive, causing uncontrolled division. This protein kinase is often called c-KIT or CD117.
Some inherited conditions (meaning it can be passed from a parent to their child) may increase a person's risk of developing soft tissue sarcomas. Diseases such as Neurofibromatosis, Gardner syndrome, Li-Fraumeni syndrome, and inherited retinoblastoma are all conditions linked to sarcoma’s diagnosis.
Ionizing radiation is a risk factor for both soft tissue and bone sarcomas, thought to be a factor in less than 5% of diagnoses. The most common cause of radiation exposure in patients who develop sarcomas is from radiation given to treat other tumors, such as breast cancer or lymphoma. The average time between radiation exposure and diagnosis of a sarcoma is about 10 years. However, advances in treatment are expected to reduce the number of secondary cancers resulting from radiation therapy.
However, sarcoma can still occur in people that have no apparent risk factors, thus making it difficult to present worthwhile prevention methods. |
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