What is Sarcoma?
Sarcoma is a rare cancer of bones and connective tissue. Connective tissue refers to a highly specialized group of issues that maintain the form of the body and provide internal support. It includes the muscles, bones, adipose tissue (fat), cartilage, ligaments, etc. There are more than 60 subtypes of sarcoma.
What are the symptoms of sarcoma?
Symptoms usually depend on the location of the disease. It can begin as a painless swelling in the arms or legs, which gradually increases in size and may become painful as the size increases. Sometimes, sarcoma originating in the thigh or pelvis can attain a very large size before it gets noticed. Sarcoma of soft tissues usually occurs in adults and older age groups. Often, the swelling is mistaken for an abscess (pus collection) and the patient is wrongly subjected to an unplanned surgery in the form of I&D (incision and drainage), which can be detrimental not only in future limb salvage but also delays the start of correct treatment.
Sarcoma originating in the bone is painful, to begin with, which worsens over time and is associated with swelling in the affected region. Bone sarcoma (Osteosarcoma, Ewing’s Sarcoma) usually occurs in growing children and young adolescents. It can cause the weakening of bones resulting in fracture. Some patients may attribute these symptoms to any prior antecedent trauma. Sometimes, these patients are wrongly being treated for infection, thus delaying the correct treatment which may have a bearing on the outcome.
In short, one should not ignore any lumps or bumps in his/ her body more so if they are increasing in size over time.
How common is sarcoma?
Sarcoma is a very rare form of cancer affecting 1 person in a million. It approximately constitutes 1% of all adult cancers.
What are the causes of sarcoma?
There are no known environmental or other hereditary factors that cause sarcoma, except for patients who have received prior radiation therapy. Certain patients are at a greater risk for bone sarcoma which includes:
- Patients with a history of Paget’s Disease
- Patients with hereditary retinoblastoma – a type of eye cancer that most commonly affects very young children
- Patients with Li-Fraumeni syndrome – a rare genetic condition
How is sarcoma diagnosed?
A patient suspected of sarcoma needs to be investigated thoroughly with blood tests, X-rays, and MRI to look for the local extent of the disease. Since sarcoma can spread to lungs and bones, staging of the disease is done either with whole-body PET CT or a bone scan with CT chest or CT chest alone depending on the type of sarcoma. Along with this, a biopsy (usually with a needle) is required to establish the diagnosis. It’s important to do a biopsy from the correct site since the wrong biopsy site can be detrimental to limb salvage and can result in amputation (cutting the limb). Therefore, it’s recommended that the biopsy should always be done by the surgeon (Orthopaedic Oncologist) who will be doing the final surgery for sarcoma.
What is a biopsy? Who should do the biopsy?
In a biopsy, some part of the tumor tissue is removed and sent for examination under a microscope. It can be an open biopsy (in which a surgical incision is made to expose the tumorous mass and take out the diseased tissue) or a needle biopsy (in which a thin needle is used to take out the tissue without any incision). Since, the needle biopsy doesn’t involve any incision, the surgical trauma, pain, and morbidity are less.
It is very important that a biopsy should always be done by a surgeon experienced with sarcomas who will be doing the definitive surgery since poorly done biopsies not only yield false-negative but also wrongly placed biopsy scars can be detrimental for future limb salvage (which might unnecessarily cause an increase in the extent of surgery and hence the complications). In a nutshell, since the location and technical aspects of the biopsy can affect the treatment options and the final outcome for the patient, it should always be done by an orthopaedic oncologist or one of his team members.
What is the treatment of sarcoma?
Treatment of sarcoma is a multidisciplinary approach requiring an orthopedic oncologist (Bone & Soft tissue tumor specialist), medical oncologist (Chemotherapy Specialist), radiation oncologist (Radiotherapy specialist), and pathologist (Specialist in tissue diagnosis).
If the sarcoma is not metastatic (not spread to any other parts of the body), it will usually involve some form of surgery to remove the cancerous tissue with a wide margin (with a cuff of normal healthy tissue around the tumor). The patient may require additional treatment in the form of radiation therapy or chemotherapy, which depends on the type of sarcoma, type of surgery, age of the patient, etc.
Soft tissue sarcomas usually require surgery with wide margin and radiation therapy, which may be given prior to surgery (pre-op RT), during surgery (brachytherapy), or after surgery (post-op RT). The patient may need chemotherapy, which is mainly determined by the sarcoma subtype and age of the patient.
Usually, in primary bone sarcomas, chemotherapy is given to the patient followed by surgery to remove the diseased bone which is further followed by adjuvant chemotherapy. Limb salvage surgery is possible nowadays for bone sarcomas in which the part of the bone involved with the tumor is removed surgically (rather than cutting the whole limb) and the defect is reconstructed with an artificial joint, thereby saving the limb. In some cases, the cancerous bone so removed is given a very high dose of radiation to kill all the cancer cells and the sterilized bone so formed is fixed back to the parent bone with the help of plates and screws, a technique commonly called Extra Corporeal Radiation Therapy (ECRT). In children, since the artificial joint will not grow as the child grows leading to unequal limb lengths over a period of time, the defect can be reconstructed with an expandable joint that can be lengthened as the child grows which allows maintaining limb length equality at the time of skeletal maturity.
In short, treatment of sarcomas is individualized based on the type of sarcoma, its location, size, the extent of spread, the age of the patient, etc.
What is chemotherapy?
Chemotherapy is anticancer therapy that slows the growth of rapidly dividing cancer cells in the body. For bone and soft tissue sarcomas, it is given intravenously and the patient requires admission to the hospital. Chemotherapy can be administered before surgery to shrink the tumor, after the surgery to kill the remaining cancer cells, or both.
What is radiation therapy?
Radiation therapy is the use of ionizing radiation to kill cancer cells. It can be given before or after surgery. It is given to decrease the chance of local recurrence (cancer coming back locally). The treatment may be given over single sitting or multiple sittings over a few days to weeks depending on the indication. Each session takes only a few minutes.
Is there a cure for sarcomas?
With the current chemotherapy regimes and advanced surgical technology, the cure is possible in up to 70% of patients with sarcomas. The cure rate depends on the type of sarcoma, its disease load, the size of the sarcoma, the extent of spread at presentation, and so on. In advanced cases also, a lot can be done to control the disease and give a quality of life to the patient.
Is it possible to prevent Sarcoma?
Since the exact cause of sarcoma is not known, as of now it’s not possible to prevent sarcoma.
Whom to consult?
The first chance is the best chance when it comes to curing sarcomas. So, it’s advisable to seek treatment from a trained orthopaedic oncologist when confronted with sarcoma to achieve maximum beneficial outcomes.
Can I go for alternative treatment?
Though several people claim to cure cancer there is no scientific evidence backing those claims. Patients falling for these alternative therapies delay their actual (evidence-based) treatment which may be detrimental. It’s always prudent to discuss with your sarcoma specialist if you are on any alternative medicines along with the conventional treatment since it may interfere with the standard treatment thereby decreasing the efficacy of conventional evidence-based treatment or increasing its side effects.
Read more about Sarcoma, Chemotherapy, Radiotherapy, Drugs used in Sarcoma here
