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Sarcoma is a rare type of cancer that arises from the soft tissue (like muscles, fat tissue, blood vessels, nerves etc) or from the bones. In India, approximately 14,637 cases of soft tissue sarcoma and 13,955 cases of bone sarcoma were reported in the year 2020.
Let us understand the basics of soft tissue sarcomas.
Why does Sarcoma happen ? Can it be prevented ?
Unfortunately, in the majority of cases, it is not known how sarcomas develop. However, in a small number of cases, there is a clearly identifiable risk factor which predisposes one to develop sarcoma. These include genetic syndromes like Neurofibromatosis, Li-Fraumeni syndrome and Hereditary Retinoblastoma. Sometimes, radiation therapy (which is used to treat a variety of cancers like breast cancer, head neck cancer) can rarely result in development of sarcomas several years after it is given (ranging from 4 years to 23 years !). There is no known way to prevent sarcomas from developing.
Where does sarcoma occur in the body ?
Sarcoma can develop in any part of the body. Half of all sarcomas develop in the extremities, with the thigh being the most common site. Around 40% of all sarcomas develop in the stomach , and rarely sarcomas can occur in the chest and head neck region as well.
How does one know if they have sarcoma ?
Patients who develop sarcoma often have a painless mass, which may be noticed incidentally when an injury happens. If a mass is noticed, one should immediately contact their oncologist who will physically examine the mass and plan a biopsy. Biopsy helps to differentiate between benign and malignant (cancerous) masses and also informs about the type of sarcoma. (There are more than 50 types !)
Once the biopsy has confirmed the diagnosis, the sarcoma has to be staged with imaging tests like CT scan, MRI scan etc so that the appropriate treatment can be planned.
Is sarcoma curable ? What is the correct treatment ?
Sarcomas are very much curable, if detected and treated early. The treatment of sarcomas depends on the size of the lesion, the grade of the tumor (which the biopsy informs us) and the location of the tumor.
It is very important that the patient be evaluated by a multidisciplinary team of oncologists ( surgeon , radiation oncologist, medical oncologist ) BEFORE any treatment is planned. This is because the correct sequence of treatment has to be individualized to each patient based on the above characteristics, which is unique to each patient.
For example, if the size of the mass is small (<5cms), then surgery is done first, and postoperative radiation can be omitted if the surgical margin (gap between cut end of tissue and actual tumor) is >1cm. If the size of the mass is >10cms, then it is better to administer radiation therapy BEFORE surgery as it controls the tumor better than giving it after surgery. Some cases also require chemotherapy, depending on the type of the sarcoma and the size of the tumor.
So, as you can see, the treatment of sarcomas is very complex, and requires a coordinated team effort to produce the best results.
Does sarcoma come back after treatment ?
In some cases, sarcoma is known to relapse. The important factors that determine whether the patient can be treated again depend on the size and the timing of recurrence. If a repeat surgery is possible (without excessive damage to nearby structures), then it should be surgically removed. Post surgery, radiation therapy can be repeated in select cases to further reduce the chances of local recurrence. Advances in radiation techniques like IMRT (Intensity modulated radiation therapy) and IORT (Intraoperative radiation therapy) can help to minimize the side effects of radiation to nearby critical structures.