A sarcoma is a cancer that starts in the connective tissues of the body. A soft tissue sarcoma is a cancer that originates from the soft connective tissues of the body such as fat, muscle, nerves, blood vessels and fibrous tissues. As these structures are present everywhere in the body, soft tissue sarcomas can arise from all parts of the body but occur more commonly in the arms and legs.A rhabdomyosarcoma is a soft tissue sarcoma which occurs mainly in childhood and accounts for about 50% of all soft tissue sarcomas in childhood. Most of these cancers occur in children less than the age of 6. Common areas where these tumours happen in the body include the head and neck area particularly around the eye, urinary tract such as the urinary bladder and the extremities such as arms and legs. There are several types of rhabdomyosarcomas which are embryonal, sclerosing, botryoid and alveolar with embryonal being the most common of them.
Risk factors for the development of this condition include inherited genetic conditions such as Li Fraumeni syndrome, Costello syndrome and Beckwith-Wiedemann syndrome.
Diagnostic tests in a patient suspected of having rhabdomyosarcoma include a biopsy of the suspected mass and IHC on the biopsy sample. This will give a confirmatory diagnosis. Following that, other genetic tests such as FISH (Fluorescence in situ hybridisation) or RT-PCR are done which helps in further diagnosis.
Other diagnostic tests include a CT scan, MRI scan or a PET-CT scan to look at the cancer and to look for spread of cancer to other parts of the body. Which scan to select will depend on the location of the primary tumour in the body. Blood tests and a lumbar puncture are also done.
Rhabdomyosarcoma is staged according to the CG staging or the TNM staging systems. The CG system is detailed below.
|The tumour is confined to one area in the body and removed completely.
|Tumour confined to one area of the body but spreading locally and removed completely.
|Tumour confined to one area, has been removed but microscopic disease still remains
|Tumour extends into the lymph nodes around it and removed but microscopic disease still remains
|Tumour localised or extensive and not removed by operation
|Tumour localised or extensive, with gross disease remaining after extensive surgery
|Presence of disease away from the area of origin (metastatic)
Treatment of rhabdomyosarcoma involves use of surgery, chemotherapy and radiotherapy. Generally, rhabdomyosarcoma is a curable disease in majority of patients particularly in the early stages. For patients with localised disease that can be removed with surgery, surgery will be the first treatment option. This will be followed up with chemotherapy and radiotherapy. The addition of chemotherapy and radiotherapy will help improve chances of cure. For patients with advanced disease that cannot be removed with surgery or for patients with disease that is present in areas of the body where surgery is risky, chemotherapy is used first followed by radiotherapy and surgery if feasible at that stage.
Chemotherapy drugs commonly are Vincristine, Dactinomycin and Cyclofosfamide and are given three weekly. When radiotherapy is used, it is given once a day for 4 to 6 weeks. For patients who have recurrence of disease, chemotherapy is used mainly as treatment to control the disease.