Sarcoma

Sarcomas are rare but aggressive tumours arise from a primitive tissue subtype known as mesoderm. It can thus affect a very wide variety of tissues and organs in the body across a wide range of age groups, from young children to the elderly. Sarcomas generally arise from soft tissue or bony sites on the body, giving rise to the broad division into soft tissue and bony sarcomas. More than 30 different subtypes of sarcomas have been described.

 

 

These are relatively rare cancers that comprise 1% of all malignancies. The NCCS sees approximately 60 cases of sarcoma in year 2013.

 

 

Different subtypes of sarcoma affect patients from different age groups; no one particular age group is more commonly afflicted with all sarcoma subtypes.

Many patients first consult a doctor because of a lump or mass on the trunk, leg or arm. The lump may or may not be painful. The sarcoma is diagnosed when biopsy (removal of piece of tissue) of a lump on the arm, leg or trunk is examined under a microscope by the pathologist (doctor who specialises in examining tissue under a microscope). Bone cancers are commoner in the shoulder and knee areas compared to other areas of the body.

When the cancer is advanced there may be weight loss, loss of appetite, or prolonged fever. Other symptoms are referable to the site of the sarcoma, such as feeling of fullness on eating, indigestion, and gastric pain when a stomach sarcoma is present and bleeding from the vagina when a uterus sarcoma is present.

For most patients, no risk factors have been identified.

 

Patients with familial diseases such as neurofibromatosis who have multiple benign enlargements of nerve sheaths have a higher risk of one of these enlarged nerve sheaths turning cancerous.

 

Patients with prior radiotherapy have a slightly higher chance of developing a sarcoma within the previously radiated area. This may take up to 10 years to occur.

Most sarcomas are diagnosed when biopsy (removal of piece of tissue) of a lump on the arm, leg or trunk is examined under a microscope by the pathologist (doctor who specialises in examining issue under a microscope).

 

Once a sarcoma is diagnosed, other tests such as magnetic resonance scanning (MRI) of the site of cancer to delineate extent of the cancer and if it is operable, computerised scans (CT) of the lungs and liver to determine if the cancer has spread, are usually arranged.

Patients who have sarcoma localised to the organ of origin have surgical removal of the entire cancer and a rim of surrounding normal tissue where possible. In some patients, additional radiotherapy to the site of cancer is required after surgery to prevent cancer recurrence at the same site. This is especially so if the cancer is large to begin with. In some particular subtypes of sarcoma, additional chemotherapy may also be required after curative surgery.

 

Radiotherapy to arms and legs is associated with redness of the skin and hair loss over the area radiated. Radiotherapy to the head and neck region is associated with temporary redness of the skin, loss of appetite, loss of salivation and dryness of the mouth. Radiotherapy to the stomach region is associated with temporary nausea and vomiting, loss of appetite, and occasional gastric pain.

Patients with osteogenic sarcoma usually require chemotherapy to prevent cancer recurrence after surgery. This chemotherapy is given into hand veins and may cause nausea and vomiting, temporary hair loss, lowering of the blood counts and occasional numbness of the fingers and toes. Selected patients with localised soft tissue sarcoma of the limb benefit from chemotherapy given after the surgery.

In patients with advanced stage sarcoma, chemotherapy can slow the course of the cancer and provide relief of cancer related symptoms. Associated side effects of chemotherapy are temporary or complete hair loss, nausea and vomiting, ringing of the ears, numbness of the fingers and toes, and loss of appetite. More serious side effects may include organ dysfunction (including the hearts, kidneys and gastrointestinal tract) and serious infections as a result of bone marrow suppression.

 

One particular subtype of sarcoma known as gastrointestinal stromal tumour (GIST), usually arises from the tissues of the stomach or small intestine. This disease can be treated with an oral medication known as Imatinib, a relatively new medication that specifically targets the mutated protein that causes the cancer, as opposed to chemotherapy that affects both normal and cancerous cells. Imatinib is used both after curative surgical removal of localized GIST, and in advanced GIST.

 

Sarcoma treatment is usually multidisciplinary, and involves doctors from many different departments. Decisions on treatment are usually made following discussions between all teams involved at multidisciplinary tumour board meetings.

Prognosis of Sarcoma

The primary determinants of prognosis in sarcoma include patient performance status, sarcoma subtype, and stage of disease at diagnosis. This will be discussed individually with each patient during their clinical consultation. In general, patients with earlier, smaller sarcomas have a more favourable prognosis than those who present with more advanced disease.

Click to watch our videos on Sarcoma, part one and part two.  For further enquiries on Sarcoma, please call the Cancer Helpline at (65) 6225 5655 or email to cancerhelpline@nccs.com.sg

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