Sarcoma: Treatments

The treatment of sarcoma generally requires a multi-disciplinary approach, involving experts in surgery, oncology (chemotherapy) and radiation, as well as orthopedic oncology, surgical oncology, neurosurgery and reconstructive or plastic surgery.

Treatment of bone sarcomas may require up to three months of chemotherapy prior to surgery with yet another course afterward, once the patient has been through the recovery process.  Therapy for this type of cancer can take up to a year, assuming there are no complications and there is no need for additional procedures.

The primary treatment for soft tissue sarcomas is surgery.   Chemotherapy can be used before surgery to shrink the size of the tumor, which increases the chance of removing the whole cancer.   Chemotherapy is also used to treat a sarcoma when it has spread to other organs or other parts of the body.  The decision to give radiation before or after surgery—or both—is made on an individual basis. 

Surgery

Surgery is the first line of treatment for soft-tissue sarcomas of the abdomen and uterus. Other types of sarcoma may require chemotherapy and/or radiation beforehand to shrink the size of the tumor before operating.

Limb-sparing Surgery:  The goal of limb-sparing surgery is to preserve as much of the muscles, ligaments and nerve as possible.  Roughly 90 percent of sarcoma patients are candidates for limb-sparing surgeries. Orthopedic surgeons, neurologists, oncology surgeons and reconstructive surgeons may collaborate on these intricate and innovative procedures.

Reconstructive surgery: After the tumor is removed, surgeons may use the following techniques to restore limb function.

  • Allografts: Some bone repairs can be accomplished using freeze-dried cadaver bones. This material is packed into small areas in the patient’s bones after tumor removal, rather like plastering over a defect in a wall.  Whole cadaver bones can be used to replace sections of the patient’s pelvis or larger bones. These then serve as scaffolding as the patient’s own bones begin to grow and cover the cadaver bone. Because allografts are associated with a high risk of infection, and can also break down over time, surgeons are developing a new technique that provides the mid-bones with a critical blood supply.
  • Metal prosthesis: A prosthesis is an artificial body part.  A metal rod is used more frequently than cadaver bones when treating children affected by sarcoma.  The reason: Additional sections can be added to the rod as the child’s body grows.  Over time, however, the metal devices may begin to loosen. For this reason surgeons sometimes combine allografts with metal inserts.
  • Expandable prosthesis: New expandable devices have been designed that actually mimic the growth of a child’s own healthy limbs. This type of prosthesis expands on its own, therefore sparing the patient several additional surgeries. This approach relies upon an electromagnetic field generated on the skin near the implant. This resulting heat releases a coiled spring inside the implant, and the device expands without any surgical intervention. This procedure can be performed on an outpatient basis, at required intervals.
  • Fibular autograft: In this technique, also used in children, small calf bones called the fibula are used to repair or replace an arm bone that has been affected by sarcoma.  A portion of the patient’s own fibula is harvested, thereby reducing the chances of infection.

Chemotherapy

Depending on the type of sarcoma, chemotherapy (treatment with anticancer drugs) may be given to shrink the original tumor.  This approach is considered the standard of care when dealing with osteosarcoma, or cancer of the bone, and is sometimes also used for soft tissue sarcomas. When chemotherapy is given before surgery, it is called neoadjuvant therapy.  Chemotherapy is also used when the tumor has spread to other organs or parts of the body.  Not all sarcomas respond well to chemotherapy, so the decision to proceed with it must be made between a patient and a doctor with expertise in this disease.  In fact, there are some sarcomas that do not respond to any chemotherapy.

Types of chemotherapy used to treat sarcomas include:  doxorubicin (adriamycin), liposomal doxorubicin (doxil), gemcitabine (Gemzar[LF1] ), docetaxel (taxotere), ifosfamide (Ifex), cyclophosphamide (Cytoxan), vincristine, etoposide (VP-16), methotrexate (specifically for osteogenic sarcoma), and decarbazine (DTIC).  These drugs can be used alone or in combination, and are at times selected based on the specific sarcoma subtype being treated.   There is also a recently approved drug called pazopanib (votrient) which is an oral form of therapy.  For GIST the c-kit inhibitors include imatinib (Gleevac), sunitinib (Sutent), and more recently regorafenib. 

Sometimes for sarcoma there are no standard, effective therapies.  In these cases patients should consider being treated on a clinical trial with an investigational therapy.  In clinical trials the latest advances in cancer therapy are offered.  Many of these trials are now based on drugs which specifically target the unique characteristics of the cancer cell.    

Isolated limb perfusion: This is a form of chemotherapy that is sometimes used.  It allows physicians to target the blood supply in an arm or leg that is affected by a tumor.  In this approach, the chemotherapy drugs are given locally, so they target the circulation supply of a particular limb.
 

Radiation Therapy

Radiation therapy is sometimes used before surgery.  When this approach is necessary, the wound may not heal as well. Plastic or reconstructive surgeons are brought in to address any structural problems, after the tumor is removed.

Radiation may also be prescribed after surgery for patients with soft-tissue sarcomas (STS) to reduce their risk of recurrence.  When treated by surgery alone, STS is more likely to grow back at the original site.  

When offering treatment post-operatively, radiation oncologists can employ a smaller dose and target its delivery more precisely, reducing the patient’s overall exposure. Another advantage of this approach is that it reduces side effects like scarring, stiffness or swelling of a limb.

The radiation most commonly used to treat soft-tissue sarcoma is External Beam Radiation Therapy meaning that radiation is delivered to the body from a machine. A technique called Intensity Modulated Radiation Therapy (IMRT) focuses the radiation on the tumor and lessens any impact on the patient’s healthy tissue.

Another option is Intraoperative Radiation Therapy (IORT), available only at a few select centers in the nation. A large dose of radiation is given in the operating room right after the tumor is removed but before the wound is closed. This means the radiation doesn't have to travel through the healthy issue sounding the tumor. Often, after IORT the patient receives some other type of radiation after surgery as well.

Brachytherapy (also called Internal Radiation Therapy) is also used to treat soft-tissue sarcoma.  This approach places small pellets (or seeds) of radioactive material in or near the cancer using very thin catheters (tubes). The pellets deliver high doses of radiation and only stay in place for minutes at a time. (In low-dose rate (LDR) brachytherapy, the pellets may stay in place for days at a time).