Sarcomas are a type of cancer, where the aggressive tumours occur on soft tissue or bones. In this video, National Cancer Centre Singapore experts share the symptoms, diagnosis and treatment methods of two common types of sarcomas.
Transcribed from video.
Did you know aggressive tumours can develop on soft tissue or bones?
The condition is called Sarcoma and although it is rare, it affects a wide range of age groups – from young patients to the elderly adults.
Sarcomas comprise 1% of all adult cancer types, with the
National Cancer Centre Singapore seeing more than 180 new sarcoma patients annually.
Types of sarcomas
Sarcomas can generally be classified into 4 major types:
- Soft Tissue Sarcomas
- Gastrointestinal Stromal Tumours (GIST)
- Bone Sarcomas
- Adolescent Young Adult Sarcomas
In this episode, we will be talking about soft tissue sarcomas and GIST, short for gastrointestinal stromal tumours.
Soft tissue sarcomas
What are the symptoms of soft tissue sarcomas?
Patients with soft tissue sarcomas generally present with a large painless abdominal mass. In some cases, they may have no symptoms and have this mass picked up as an incidental finding when doing an investigation for unrelated conditions and symptoms.
Diagnosing soft tissue sarcomas
Often, after a complete history taking and thorough physical examination, it is still difficult to find the diagnosis. Further imaging via a CT scan or an MRI scan is required to determine where this tumour is from and exactly what kind of tumour it is.
Sometimes, a diagnosis can only be attained if a biopsy is performed. This can be done via one of two methods:
Percutaneous (through the skin) method
An interventional radiologist, using the guidance of a CT scan or ultrasound, places the needle
through the skin to arrive at the tumour, to obtain the biopsy.
A scope is passed through an organ, such as the stomach or rectum. Through the scope, a biopsy is taken with a needle.
Treatment for soft tissue sarcoma
Very often, the procedure would not take very long and may just be a few hours. After the procedure, the patient is usually asked to stay for the day or overnight and can be discharged the next day if there are no complications.
In some patients, radiotherapy to the operated site may be required 4 to 6 weeks after surgery to prevent recurrence there.
This is especially so if the tumour was large or is of an aggressive type.
- The patient will first undergo a specialized CT scan of the operated site in the treatment position, with suitable immobilization devices.
- A targeted and comprehensive radiotherapy treatment plan then needs to be developed by a team of experts consisting of the radiation oncologist, physicist and dosimetrist. The treatment plan will be developed within 1 to 2 weeks.
- Treatment involves the delivery of therapeutic x-rays to the operated site by a machine called a linear accelerator. The patient does not feel anything during treatment, which takes a few minutes. This is done every weekday for around six weeks.
Gastrointestinal stromal tumour (GIST)
Another kind of sarcoma is called Gastrointestinal stromal tumour or GIST for short. This condition generally arises from the tissues of the stomach, the small intestine or in the large intestine, like the colon or rectum.
Symptoms of gastrointestinal stromal tumours (GIST)
Patients with GIST may not have any symptoms at all, or they may present with a mass that they have palpated. They may also have symptoms as a result of obstruction or blockage caused by this mass. In this situation, the patient usually experiences fullness after eating or they may have discomfort, distention and even vomiting, as a result of obstruction by this mass.
Treatment for gastrointestinal stromal tumours (GIST)
Patients with GIST are often treated by surgery, especially if the tumours are confined to an organ. The surgery's main goal is to remove the whole tumour, along with the organ that is involved. It is important to ensure that no tumour is left behind and clear margins are attained.
After surgery, we give chemotherapy to some patients with GIST, to prevent cancer relapse. This form of chemotherapy is administered orally and targets the abnormal protein causing the cancer. This treatment not only delays relapse but also improves survival.
Other more common forms of sarcoma who may require preventive chemotherapy include osteosarcoma (bone sarcoma) and Ewing sarcoma.
We have come to the end of part one of our sarcoma series. Please join us for part two, where we will be talking about bone sarcomas and Ewing sarcomas.
To learn more about sarcoma, you can contact the
National Cancer Centre Singapore at 6436 8000 or visit