Cancer is a disease which results from uncontrolled growth of abnormal cells in the body. Due to various reasons our body cells may start to behave abnormal and when these abnormal behaving cells start to divide, they can divide in uncontrollable way and form a mass called tumor which can be benign or malignant.
Benign is the tumor that remains enclosed in one place (does not spread) while malignant is the one that can spread to other sites of the body. Malignant tumor is also called cancer.
Ewing sarcoma is the type of cancer that start in the bones or nearby soft tissues. Ewing sarcomas are different from other bone cancers. These sarcomas have some similar cellular physiological and genetic features which are different from other bone cancers. Ewing sarcoma commonly affect children and young adults from the age of 10 to 20 years. Also statistics shows that, number of men (boys) who are affected by this cancer is slightly higher compared to that of women (girls).
Types of Ewing sarcoma
Ewing sarcoma can be classified depending on location of that cancer in the body. There are mainly four groups of Ewing sarcomas;
• Bone tumors: This is the type of Ewing sarcoma where the tumor starts in the bones. Bones that are mostly involved in this type of cancer include pelvis, femur (thigh bones), ribs, humerus and clavicle.
• Soft tissue (extra-osseous) tumor: These are the tumors that affects soft tissues surrounding bones. This include those affecting cartilages and muscles.
• Peripheral primitive neuroectodermal tumor (pPNET). This type of tumor affect nerves.
• Askin Ewing sarcoma. This is the type of pPNET that is develop in the chest wall.
Risk factors of Ewing sarcoma
When it comes to cancer, anything that increases your probability of developing cancer is called a risk factor. Risk factors only influence development of cancer but it does not directly cause cancer. Sometimes people with risk factors do not develop the disease while those with no risk factors do develop the disease. Knowing risk factors will help you live your life making some better healthy choices to reduce the risk.
In case of Ewing sarcoma, till now there are no any proven external factors like exposure to chemicals, exposure to radiations or any other environmental factors linked with this cancer.
Most of Ewing sarcoma cases are linked with genetic defect caused by chromosomal translocations of genetic materials. This means that genetic materials have swapped places inside normal cells which makes these cells to become abnormal and divide to form tumors.
This disease is not inherited, that means these genetic defects are not passed from parents to children.
Usually this translocation is between chromosomes 11 and 22 but also it can happen between chromosomes 17 and 22, 7 and 22 also it can happen between chromosomes 21 and 22.
Other factors that may increase someone`s risk of developing Ewing sarcoma includes;
• Age. This cancer is more common to children and young adults at the age of 10 to 20 years
• Gender. The number of boys affected by this kind of cancer is slightly higher than the number of girls.
Since there are no external or environmental factors or any life style that are associated with this type of cancer, until now it is not possible to prevent against this type of cancer. The only known risk factors are genetic factor, age and gender that cannot be changed hence it is difficult to prevent against this type of cancer.
Early detection and screening
Screening is the process of running some tests to someone who doesn`t have any symptoms of a disease to see if he/she is affected by the disease although there are no shown symptoms and signs. This process has proven to be helpful to some extent in saving lives as some people come to realize that they have cancer at an early stage through some tests after screening tests reveals cancerous cells.
But for Ewing sarcoma, till now there are no wide recommended screening tests that would help in detecting this cancer at an early stage. Despite of absence screening tests for this cancer, most cases are revealed while they are still at an early stage through signs and symptoms. So when you experience symptoms that relate to those of Ewing sarcoma it is better to go to the hospital for more checkups.
Signs and symptoms
Children and teens with Ewing sarcoma may experience some of the following signs and symptoms. Sometimes these signs and symptoms may be caused by other medical conditions so seeing the doctor upon experiencing some symptoms is very important.
Among the signs and symptoms of Ewing sarcoma include the following;
• Stiffness, tenderness, pain or swelling in the bones or nearby tissues is among the common symptom caused by Ewing sarcoma.
• A lump near the skin which feels warm or soft upon touch
• Back pain which may be the indication of paraspinal, retroperitoneal or deep pelvic tumor.
• Systemic symptoms of fever and weight loss which may indicate metastasis of tumor.
• Broken bones without any known usual cause of break
• Paralysis or loss of bladder control which may occur if spine is affected.
Medical diagnosis simply means identification of nature of an illness by elimination of the symptoms. Normally people don`t go to hospital knowing they have cancer but during diagnostic procedures is when doctors detect the disease.
Following suspicion of the disease, doctors normally run combination of tests to determine whether there are cancerous cells in the body or not and if there are cancer cells, how far have they spread. Along with thorough medical history and physical examination, doctors normally use combination of the following tests to diagnose cancer.
Laboratory tests are important in ruling out other conditions and confirming diagnosis. For cancer diagnosis laboratory tests normally include blood tests, urine tests, tumor markers and other body fluids tests.
• Blood tests. Blood tests help to reveal level of different substances in the blood which will help doctors to know if there is anything wrong in the body. From blood tests doctors can see complete blood count which indicates number, size and maturity of blood cells. Also from the blood tests doctors can analyze if kidney and liver are working properly.
• Urine tests. Urine tests (urinalysis) involve laboratory examination of urine to check presence of blood, proteins, and other substances such as drugs. For instance blood in the urine may be an indication of benign condition, infection or other health problem.
• Tumor markers. These are biomarkers (proteins) that can be produced by both cancer cells and normal body cells in response to cancer. Tumor markers are released into the blood or urine. Although studies are still conducted to determine role of these markers in diagnosing cancer because sometimes people with benign condition will have elevated level of these proteins. Also not all tumors have their markers and some markers are not specific to one type of tumor.
• Other body fluids. Despite being rarely used, sometimes body fluids can be tested in the lab during diagnosis of cancer. For instance the use of cerebral spinal fluid (CSF) and pleural fluid. CSF is used in diagnosis of brain tumors while pleural fluid for lung cancer.
Diagnostic imagings involve tests that create pictures of inside the body that help the doctor to see if there is tumor or not. There are several imaging tests used in cancer diagnosis depending on the type and location of cancer suspected. These imaging tests include;
• Computed tomography (CT) scan. CT scan machine is a donut-shaped scanner that uses x-rays to create series of pictures of body organs from different angles. This machine is linked to a computer where those series of pictures taken will be combined to create a 3D- image of inside the body. During the scanning process patient will lie still on the table which will slide into the scanner. In order to get a clear image, sometimes the doctor will inject the patient with a contrast material before scanning. From the images the doctor will be able to differentiate between healthy and unhealthy tissues.
• Magnetic resonance imaging (MRI). MRI is an imaging technique that uses powerful magnet and radio waves to take series of pictures of body organs and create a 3D image in a computer linked to a machine. Just like in CT, during MRI procedure the patient will lie on a table that will slide into a long round chamber. Also during this procedure the doctor may inject the patient with a contrast material for clear image view.
• X-ray. This is an imaging technique that is uses low dose of radiation to create pictures of inside your body. Technician will position the patient and direct the x-ray beam to the intended part of the body.
• Ultrasound. Ultrasound is a diagnostic imaging procedure that uses high energy sound waves to produce images of organs inside the body. During the examination, a patient will lie on the table while the technician will slowly move a device called transducer on the skin over the part of the body that is being examined.
• PET scan. Positron emission tomography (PET) scan is an imaging test that uses radioactive glucose to create 3-D images of areas inside the body. Radioactive glucose is used for this test because cancer cells tend to absorb more glucose than normal body cells, so the scan will show which areas of the body has more glucose than others. Before the scan, doctor will inject the patient with tracer called radioactive glucose then during imaging the patient will be asked to lie on the table that will be moving back and forth through the scanner.
• Bone scan. Bone scan is used to examine bones. When it comes to cancer, bone scan is used for diagnosis of bone cancer or cancer that has metastasized into the bones. Before the test, patient will be injected with small amount of radioactive material that tends to collect more on abnormal parts of the bones. Then pictures that will be taken by a scan will indicate the distribution of those radioactive materials in the bones throughout the body.
Biopsy is a diagnostic procedure that involves removing a tissue sample from the body and examines it under microscope in the laboratory. Examination in the laboratory is normally done by a pathologist who will check if the cells in the tissue are cancerous or not. In most cancer cases, biopsy is considered to be the confirmatory test. Depending on the location and type of cancer, biopsy can be obtained in different ways. Some of them include;
• Using needle. By using a thin needle, doctors can draw same tissue or fluid for examination under microscope. This method can be used to draw some fluid (spinal tap), bone marrow (bone marrow aspiration), blood or small amount of tumor from the suspected organ such as liver and breast (fine needle aspiration).
• Surgery. Abnormal tissue samples are obtained while the doctor is performing the surgery. Tissues are then sent to the lab for examination during the surgery. If the surgeon removes just a portion of abnormal area it is called incisional biopsy while when the entire tumor (abnormal site) is removed it is called excisional biopsy.
• Using endoscope. Endoscope is a thin, lighted tube with a camera (focusing telescope) at the end. It is used for viewing inside the body through natural openings like mouth and anus. During an examination if the doctor sees any abnormal tissue, then endoscope can also be used to take sample for that tissue. There are different kinds of endoscopy exams depending on the site of the body being examined. Some of the exams include colonoscopy (for rectum and colon), bronchoscopy (for trachea, bronchi and lungs) and esophagogastroduodenoscopy EGD (for esophagus, stomach and duodenum)
In addition to physical examination, diagnosis of Ewing sarcoma involves running several tests including complete blood count (CBC) through which doctors may also check for presence of enzyme called lactate dehydrogenase (LDH) which may sometimes indicate presence of this cancer in the body, X-ray, CT scan, MRI Scan, PET Scan, Bone Scan, Biopsy and Bone marrow aspiration.
Staging is a process of describing the location tumor, whether the tumor has spread or not and if it has spread, then which organs or parts of the body involved. Staging helps doctors plan for suitable treatment and also are able to predict its probability of recovery.
Most cancers have their own staging descriptions. However till now there is no specific staging system for Ewing sarcoma. Since there is no staging system for this Ewing sarcoma doctors plan treatment for Ewing sarcoma cases by considering the following;
• Localized tumor. Localized tumor means tumor is still at its original site, so even treatment will be planned basing on that.
• Metastatic Ewing sarcoma. This is the one that has spread to other parts of the body. So when planning for treatment, doctors will chose treatment options that will cover even other affected body parts.
When it comes to treatment of cancer, usually treatment option and planning depends on the size of tumor, whether the disease has spread to other parts of the body, general health of the patient and patient’s treatment choice.
Just like other cancer types, treatment of Ewing sarcoma requires effort from a team called multidisciplinary team which include specialists like medical oncologist, surgical or orthopedic oncologist, radiation oncologist, radiologist, pathologist and other health care team including dietitian, occupational and physical therapist. Among the treatment options used for treatment of Ewing sarcoma include the following;
Chemotherapy is the treatment option that involve using drugs to destroy or stop growth of cancer cells. Generally chemotherapy is can be given through injection into vein (intravenously) by using a needle or given as a pill or capsule that is swallowed (orally). This treatment is given by a specialized doctor known as medical oncologist. For treatment of Ewing sarcoma chemotherapy is usually injected into a vein or muscle, it is rarely given as a pill. For Ewing sarcoma, chemotherapy is usually used as primary treatment option and can be combined with either surgery or radiation therapy.
Side effects of chemotherapy and management
Usually the side effects go away soon after completing treatment. But if some of those symptoms become severe during treatment, doctors may provide some medication to relieve them. Some of the possible side effects of chemotherapy for Ewing sarcoma include the following;
• Nausea and vomiting
• Loss of appetite
• Hair loss
• Risk of infection
This is the treatment option that involves removal of tumor and some surrounding healthy tissues through operation. This treatment option helps to prevent tumor from spreading and affecting other organs. In some cases you may have to amputate an arm or a leg if tumor has spread a lot.
Side effect of surgery and management
Usually surgery is done in such a way that, it doesn`t bring disability to the patient. However if a case involves removing much of bone or even amputate the entire arm or leg, then the ability of body to function is going to be affected. In such case graft of bones from other organs may be used to reconstruct removed part of bone or prosthesis made of metal or plastic bones or joints may be used to replace lost tissues.
Physiotherapist may help children and teens learn to use the limb again. Also support services are available to help patients cope with the emotional effects of the loss of a limb
Radiation therapy is the treatment option that involve using high energy X-rays and other sources of radiations to kill cancer cells. For Ewing sarcoma, normally radiation therapy is used when surgery did not remove all tumor cells or chemotherapy is not effective. For treatment of Ewing sarcoma, external beam radiation radiotherapy is used. External beam radiation therapy is a type of radiotherapy where beam of radiation is directed to the site with tumor for the machine which is outside the body.
Side effects and management of radiation therapy
Side effects of radiation therapy depend on the dose given. Normally the side effects disappear after completion of treatment. Although if they become too severe during the course of treatment. Doctors may prescribe medications to relieve them. Some of the possible side effects include the following,
• Loose bowel movement
• Stomach upset
• Mild skin reactions.