Ewing sarcoma

Ewing sarcoma is a type of tumour that develops in bone or soft tissue from a specific type of cell. The bones of the legs, arms, feet, hands, chest, pelvis, spine, and skull can all be affected by Ewing sarcoma. Ewing sarcoma can also be detected in the soft tissue of the trunk, arms, legs, head, neck, retroperitoneum (the area behind the tissue that lines the abdominal wall and protects most of the organs in the abdomen), and other places.

Adolescents and young adults are the most commonly affected by Ewing sarcoma (teens through mid-20s).

Peripheral primitive neuroectodermal tumour, Askin tumour (Ewing sarcoma of the chest wall), extraosseous Ewing sarcoma (Ewing sarcoma in tissue other than bone), and Ewing sarcoma family of cancers are all terms used to describe Ewing sarcoma.

Ewing sarcoma is an uncommon bone tumour that mostly affects teenagers. It can also occur in soft tissue outside of the bone (extraosseous Ewing sarcoma). The tumour Ewing sarcoma is associated to is called primitive neuroectodermal tumour (PNET). Researchers discovered that these malignancies share similar physiological properties and are linked to the same chromosomal defect (balanced reciprocal translocation). As a result, these tumours are commonly referred to as the Ewing family of tumours (EFT). Ewing sarcoma of the bone, extraosseous Ewing sarcoma, primitive neuroectodermal tumour, and Askin’s tumour are all included under one umbrella term (a tumour of the chest wall). Ewing sarcoma of the bone is responsible for over 70% of the cancers in this family. Ewing sarcoma is the chosen term because, despite the several labels, it is one tumour molecularly. The long bone in the legs (femur) and flat bones in the pelvis and chest are the most commonly affected by Ewing sarcoma of bone. Ewing sarcoma is a malignancy that can spread (metastasize) to the lungs, other bones, and bone marrow, posing a serious threat to one’s life. There is no known cause for these tumours.

Dr. James Ewing initially described Ewing sarcoma in the medical literature in 1921. Ewing sarcoma is the second most frequent primary bone tumour in children, accounting for about 2% of all cancer diagnoses in children.

For details on Ewing sarcoma, please visit:

https://www.cancer.gov/types/bone/patient/ewing-treatment-pdq

Signs & symptoms of Ewing sarcoma

Signs and symptoms of Ewing sarcoma include:

• Pain, swelling or tenderness near the affected area
• Bone pain
• Unexplained tiredness
• Fever with no known cause
• Losing weight without trying

A tumour from the Ewing family of tumours can cause discomfort, soreness, and swelling around the affected area of the body. Initially, pain may come and go (intermittently), but it will soon become more consistent. There may also be numbness and weakness in the affected area. Fever, fatigue, weight loss, low levels of circulating red blood cells (anaemia), and elevated levels of circulating white blood cells are all possible symptoms in certain people (leukocytosis). Frequently, a palpable bulk is present.

The central portion (diaphyseal region) of the long bones of the arms and legs, particularly the long bone of the leg, is most commonly affected by Ewing sarcoma (femur). Flat bones, such as those in the pelvis, chest wall, and spinal column, are frequently affected by these tumours (vertebrae). Ewing sarcoma can develop in any bone in the body, including the foot, hand, lower jaw (mandible), skull, and other areas. The trunk and chest are the most common sites for soft tissue tumours. The pelvis, however, is the most prevalent site of presentation, accounting for roughly 25% of cases. Ewing sarcoma weakens bones, which can lead to fractures.

These tumours are frequently aggressive and have the potential to spread (metastasize) to other parts of the body, including other bones and the lungs. The bone marrow may become involved in rare circumstances.

The symptoms of these tumours are dependent on their location. A tumour in the leg, for example, can cause a limp, a tumour in the lungs can cause breathing issues as well as an accumulation of fluid in the tissue layers that line the lungs and chest cavity (pleural effusion), and a tumour in the spinal column can induce weakness or paralysis of affected muscles (paraplegia).

Causes of Ewing sarcoma

Ewing sarcoma has no recognised cause, and the underlying cell type has not been discovered. The majority of incidents are assumed to occur at random and for no apparent reason (sporadically).

Ewing sarcoma cells are generally defined by an aberrant shift in their genetic makeup known as a reciprocal translocation, according to chromosomal (cytogenetic) research. Pieces of two different chromosomes break off and “change places” in a reciprocal translocation. The genetic information for each individual is carried by chromosomes, which are found in the nucleus of human cells. Human chromosomal pairs are numbered 1 through 22, plus a 23rd pair of sex chromosomes that includes one X and one Y chromosome in males and two X chromosomes in females. Each chromosome has a short and long arm, denoted by the letters “p” and “q,” respectively. Chromosomes are further subdivided into numerous numbered bands.

The long arms (q) of chromosome 11 and 22 are the chromosomal locations involved in Ewing sarcoma (11q24-22q12). These fragments separate and swap positions. In the majority of cases, this causes an aberrant fusion of two genes, commonly the EWS and FLI genes. Genes create (encode) proteins that serve a variety of activities in the body. The EWS and FLI genes fuse abnormally, resulting in a “fusion” gene that produces an aberrant protein product. Although the particular activities or consequences of this aberrant protein are still unknown, researchers believe it may contribute to or influence the development of Ewing sarcoma. The cause of chromosomal translocation between chromosomes 11 and 22 is unknown as well. However, according to some estimates, this translocation can be found in more than 85 percent of tumours in the Ewing family. The EWS gene may fuse with a gene other than FLI on a rare occasion; these are usually genes from the same family as FLI1, with the gene ERG being the most common example.

Ewing sarcoma can occur as a late-onset consequence of prior treatment for another type of cancer in extremely rare circumstances.

Diagnosis of Ewing sarcoma

A thorough clinical evaluation, identification of typical symptoms and physical abnormalities, a full patient history, and a range of specialist testing are used to diagnose a tumour in the Ewing family of cancers. Microscopic examination of tumour cells and damaged tissue (histopathology) as well as molecular analysis to look for the EWS-FLI1 translocation are examples of such tests.

Clinical Evaluation and Follow-up

X-rays may be obtained first, especially if a palpable lump is present. Images of the tumour or affected area are obtained using X-rays. More advanced imaging techniques may be performed to assess the tumor’s size, location, and extension (e.g., into soft tissue or bone marrow), to identify whether the tumour has spread (metastasized) to other parts of the body (e.g., the lungs and other bones), and to aid future surgical procedures. Computerized tomography (CT) scanning, magnetic resonance imaging (MRI), and bone scans are examples of imaging techniques. A bone marrow biopsy can identify whether or not the malignancy has progressed to the bone marrow.

The surgical excision (biopsy) and microscopic examination of a section of afflicted tissue can be used to diagnose Ewing sarcoma. CD99 is a specific surface protein identified on the majority of cancers in the Ewing family. The presence of this protein could help with the diagnosis of Ewing sarcoma.

Polymerase chain reaction is another test used to identify Ewing sarcoma (PCR). PCR, or polymerase chain reaction, is a scientific technique that has been compared to “photocopying.” It allows scientists to expand and copy DNA sequences repeatedly. As a result, they can examine DNA more closely and detect genes and genetic alterations more quickly, such as the reciprocal translocation that is characteristic of Ewing sarcoma. This test is only available for study.

Treatment of Ewing sarcoma

Physicians who specialise in the diagnosis and treatment of cancer in children (paediatric oncologists), adult oncologists, specialists in the use of radiation to treat cancer (radiation oncologists), surgeons (orthopaedic surgeons), oncology nurses, and other specialists may be needed to manage people with Ewing sarcoma (depending upon the primary tumour site).

Various factors, such as the primary tumour location, the extent of the primary tumour (stage), and the degree of malignancy (grade); whether the tumour has spread to lymph nodes or distant sites; the individual’s age and general health; and/or other elements, may influence specific therapeutic procedures and interventions. Physicians and other members of the health care team should make decisions about the use of specific interventions in close consultation with the patient, based on the specifics of his or her case, a thorough discussion of the potential benefits and risks, patient preference, and other relevant factors.

Because Ewing sarcoma can cause anxiety, stress, and acute psychological anguish, people with the disease and their families are urged to seek therapy after a diagnosis and before treatment. Affected individuals and their families should seek professional counselling and psychological help, as well as participate in support groups.

Multiple anticancer medications (chemotherapy) are used in combination with surgical techniques and/or radiation to treat people with cancers in the Ewing family. The main tumour location is treated with either surgical excision of the malignancy and damaged tissue or radiotherapy. Chemotherapy kills cancer cells both in the initial site and cancer cells that have spread to other parts of the body. In most cases, systemic chemotherapy is given first, then surgery or radiation. Combination therapy has proven to be significantly more effective than surgery or radiation therapy alone. Radiation is frequently used to treat inoperable tumours and, in rare cases, metastatic cancer.

Because different medications have different modes of action in eliminating tumour cells and/or preventing them from replicating, doctors use multiple chemotherapeutic treatments. Doxorubicin, vincristine, cyclophosphamide, dactinomycin, ifosfamide, and etoposide are some of the chemotherapy medications commonly used to treat Ewing sarcoma patients.

Chemotherapy in Ewing sarcoma

These are some common chemo medicines used to treat Ewing sarcoma:

• Cyclophosphamide

• Doxorubicin

• Etoposide

• Ifosfamide

• Vincristine

Chemo for Ewing sarcoma is given as a combination of medicines. The most common combo used is vincristine, doxorubicin, and cyclophosphamide, alternating with ifosfamide and etoposide. You may hear this called VDC/IE.

Chemotherapy is a treatment that uses strong chemicals to kill cancer cells. Chemotherapy usually consists of two or more medications that are given as an IV infusion, a tablet, or a combination of both.

Chemotherapy is generally used to treat Ewing sarcoma. The medications may cause the tumour to shrink, making it easier to surgically remove the malignancy or target it with radiation therapy.

Chemotherapy treatments may be continued after surgery or radiation therapy to destroy any remaining cancer cells.

Chemotherapy may be used to reduce pain and delay the progression of advanced cancer that has spread to other parts of the body.

Surgery in Ewing sarcoma

The purpose of surgery is to eliminate all cancer cells. However, when arranging the operation, keep in mind how it will effect your capacity to go about your everyday routine.

Ewing sarcoma surgery can include removing a tiny part of bone or a whole limb. The size and location of the tumour, as well as whether it shrinks following treatment, determine whether surgeons can remove all of the cancer without taking the entire leg.

Radiation therapy in Ewing sarcoma

To kill cancer cells, radiation therapy uses high-energy beams such as X-rays and protons.

The energy beams are provided by a machine that moves around you as you lie on a table during radiation therapy. To decrease the chance of damaging surrounding healthy cells, the beams are precisely guided to the Ewing sarcoma location.

After surgery, radiation therapy may be suggested to eradicate any cancer cells that remain. If the Ewing sarcoma is located in a location of the body where surgery is not possible or would result in undesirable functional consequences, it can also be used instead of surgery (such as loss of bowel or bladder function).

Radiation therapy can help reduce discomfort and delay the progression of advanced Ewing sarcomas.

Targeted therapy

Targeted therapy is a sort of treatment that identifies and attacks specific cancer cells using medicines or other chemicals. Targeted therapies are less likely than chemotherapy or radiation therapy to kill normal cells. The following are examples of targeted medicines used to treat Ewing sarcoma.

Monoclonal antibodies are immune system proteins that are created in the lab to treat a variety of disorders, including cancer. These antibodies can adhere to a specific target on cancer cells or other cells that may aid cancer cell growth as a cancer treatment. The antibodies can then kill cancer cells, stop them from growing, or prevent them from spreading. Infusions of monoclonal antibodies are administered. They can be utilised on their own or to deliver medications, poisons, or radioactive material to cancer cells directly. Ganitumab is a monoclonal antibody that is being researched as a treatment for metastatic Ewing sarcoma.

• Kinase inhibitor therapy: This treatment blocks a protein needed for cancer cells to divide. Cabozantinib is a kinase inhibitor being studied to treat recurrent Ewing sarcoma.
• NEDD8-activating enzyme (NAE) inhibitor therapy: NAE inhibitors are drugs that attach to NAE and stop the cancer cells from dividing. Pevonedistat is an NAE inhibitor being studied to treat recurrent Ewing sarcoma.

Immunotherapy

Immunotherapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This cancer treatment is a type of biologic therapy.