Diagnosis of Ewing’s sarcoma
The importance of early diagnosis of Ewing’s sarcoma, or indeed any cancer, cannot be overstated. If a patient experiences any of the symptoms they should consult their GP at the earliest opportunity.
“Presentation” is the term used by medical professionals to describe the first time a patient attends a doctor regarding their symptoms. This can be a GP, a clinic or an emergency department. In most cases of Ewing’s sarcoma the patient will visit their GP.
The doctor will document a “clinical history” which is general information about the symptoms. They will then examine the affected area, to discover whether it hurts to touch and whether the pain is in the bone or muscle. At this stage, the doctor will be investigating for soft tissue and muscle injuries.
If the doctor is concerned that there is a possible tumour, there are national guidelines that they should follow. National Institute for Clinical Excellence (NICE) guidelines for suspected bone cancer recommend that a patient must receive an urgent referral to hospital for an X-ray.
On arrival at the hospital, the patient will undergo an X-ray to produce an image of the bone in the affected area. If the X-ray shows signs of abnormal bone growth, the hospital will conduct more detailed scans of the bone using CT (computerised tomography) or MRI (magnetic resonance imaging).
CT scans are often undertaken after the diagnosis of cancer is confirmed to determine whether it is localised (contained in the bone) or is metastatic (has spread). These scans involve the injection of contrast, before a camera rotates extremely fast around the body taking a number of images to build up a 3D picture of the body.
MRI scans use magnetism and radio waves to build a detailed 3D image of the affected bone. The hospital might also carry out a blood test to check the overall health of the patient, although at present there is no specific blood test for Ewing’s sarcoma.
If the detailed scans confirm an abnormal growth or tumour, the hospital will refer a patient to a specialist Bone Tumour Centre.
Bone Tumour Centres (‘BTC’) are hospitals that specialise in the diagnosis and surgical treatment of bone cancer. In England, there are five BTCs at Birmingham, Newcastle, Oswestry, Oxford and Stanmore. Patients in Wales usually travel to Oswestry or Birmingham and in Scotland, the three BTCs can be found in Edinburgh, Glasgow and Aberdeen. In Northern Ireland, patients are usually seen in Belfast.
At the BTC, a multidisciplinary team (MDT) will manage a patient. This team is a group of healthcare professionals who are experts in their various fields and they work together to ensure a patient is properly diagnosed and if necessary, treated. An MDT may consist of:
- An oncologist who is a doctor with expertise in managing patients with cancer. Oncologists specialise in drug treatment and radiation therapy (radiotherapy).
- A radiologist who is a doctor with expertise in interpreting X-rays and scans.
- A histopathologist who is a doctor with expertise in the microscopic examination of tissue and cells.
- An orthopaedic oncology surgeon who is an expert at removing tumours and reconstructing bone.
- A sarcoma nurse specialist who has undergone highly specialised training in caring for patients with sarcoma.
At the BTC, the MDT will assess the scans taken at the initial hospital and organise for the patient to receive a biopsy. This is the use of a core needle to take a sample of cells from the suspected tumour area, often performed under general anaesthetic. The histopathologist will assess the biopsy under a microscope and look for abnormal cells that may confirm Ewing’s sarcoma.
Together with the scan and biopsy results, the MDT will determine whether a patient has Ewing’s sarcoma or not. If not, other possible conditions include:
- Another type of bone cancer, for example, osteosarcoma.
- Eosinophilic granuloma, which is a non-cancerous bone tumour that is found mainly in children under the age of 10 years.
- Osteomyelitis, which is an infection inside the bone.
If Ewing’s sarcoma is confirmed, most patients will be referred to their nearest sarcoma oncology treatment centre. The patient will usually start treatment within a few days under the direction of the MDT, who are based at the BTC.
The National Ewing’s sarcoma Multidisciplinary Team Meeting was formed in 2011 and is a unique national forum set up to improve the treatment planning and choices made for Ewing’s sarcoma patients. This forum brings together clinicians and specialists from around the UK to discuss the treatment management and plans for current patients.
Treatment of Ewing’s sarcoma
Patients with Ewing’s sarcoma have different treatment plans depending on the location and stage of the disease. Typically, treatment for Ewing’s sarcoma involves killing cancer cells throughout the body with chemotherapy, then treatment of the primary tumour with surgery and/or radiotherapy. Chemotherapy is usually given again after these initial treatments to try and make sure there are no cancer cells left anywhere in the body.
In addition to the multidisciplinary team during a patient’s treatment, they will also be looked after by other health professionals including nurse specialists, physiotherapists to help with rehabilitation after surgery, dieticians to ensure proper nutrition and social workers/psychologists to help with emotional, social and educational needs.
Types of Treatment
Chemotherapy given before surgery is called “neoadjuvant chemotherapy”. Patients are given a combination of chemotherapy drugs. In Ewing’s sarcoma, drugs are usually delivered as an injection or infusion directly into the blood. The aim of treatment at this stage is to shrink the tumour and kill any cancer cells that may have already spread.
Although the exact treatment plan and chemotherapy drugs used may vary as part of multinational trials, such as Euro Ewing 2012, the most common treatment for Ewing’s sarcoma before surgery is the combined use of four chemotherapy drugs given together. These drugs are vincristine, ifosfamide, doxorubicin and etoposide. This combination of drugs is called “VIDE”. The purpose of using four different drugs is to maximise their effect. If the cancer stops responding to one of the drugs then the aim is that the other drugs will still be effective in killing the cancer cells.
Each course of VIDE is given over 3-4 days every 3 weeks (1 cycle) for 6 cycles. This takes about 18 weeks in total. Response to treatment is regularly assessed by MRI scans throughout this period and the patient will be seen frequently by their medical team to assess chemotherapy side effects and toxicity.
Each patient responds differently to chemotherapy. Some patients may have a very mild reaction, other patients may react strongly. Typical symptoms can include:
- Nausea (feeling sick)
- Loss of appetite
- Hair loss
- Dry mouth and ulcers
There is research to show that light exercise such as walking and swimming can help alleviate some of the symptoms.
Radiotherapy is designed to treat the tumour and not the whole body. Radiotherapy involves using high energy particles or waves, such as X-rays and gamma waves, to kill the cancer cells that make up the tumour. The high energy beams damage the DNA inside cancer cells to prevent the cells from dividing and cause them to die. Radiotherapy is usually given as a single dose each day (a few minutes) for 5-6 weeks. The symptoms of radiotherapy are similar to chemotherapy but may also include sore skin where the energy beams are focused. Radiotherapy can be given during chemotherapy cycles, before and after surgery.
A new type of radiotherapy called proton beam therapy is now offered to certain patients in the UK. This type of radiotherapy uses proton beams instead of x-ray beams. Although the radiotherapy dose to the tumour is essentially the same, protons cause less damage to the tissues they pass through. This means that doctors can administer a high dose of radiotherapy, with less effect on normal healthy tissue. The two proton beam therapy centres are at the Christie Hospital in Manchester and UCLH in London.
The multidisciplinary team at the Bone Tumour Centre makes the decision whether surgery is possible. There are two aims of surgery:
- to remove the tumour from the body,
- to reconstruct the resulting bone defect.
Surgeons have developed different surgical techniques in reconstructing the bone after removal of the Ewing’s sarcoma in order to preserve the function of the limb. The most commonly used reconstructive technique is replacement of the affected bone with a metal implant (prosthesis).
Other techniques for reconstruction include:
- bone transfer (usually the fibula bone from the lower leg or part of the pelvic bone),
- allografts (where donated bone from a bone bank is used to rebuild the limb), and
- irradiation/re-implantation which involves removing the bone containing the tumour and treating with a very high dose of radiotherapy; the bone can then be put back into the patient).
Despite advances in surgical techniques around 10% of patients require an amputation (removal of the limb) to safely remove the tumour. A prosthetic (artificial) limb can be made for the patient in these cases.
All types of surgery to remove tumours can be very complicated and require careful individual planning for each patient, including patients undergoing a planned surgical resection (i.e. removal of all or part of tissue, structure or organ). All patients undergoing planned surgical resection of Ewing’s sarcoma are discussed before surgery at the National Ewing’s sarcoma Multidisciplinary Team Meeting.
“Adjuvant chemotherapy” is chemotherapy that is given after surgery. The aim is to clear up any remaining cancer cells that have survived the previous treatments. The number of chemotherapy drugs and length of treatment will vary and again is usually as part of a multinational trial. The most common chemotherapy regime after surgery for Ewing’s sarcoma is a combination of three to four drugs – vincristine, actinomycin D plusifosfamide or cyclophosphamide. Adjuvant chemotherapy usually lasts for 24 weeks after surgery.