Tuesday 11 October 2011

Treatment of Localized Osteosarcoma

Your surgeon will remove the cancer with limb-salvage surgery, if possible. If the tumor has grown into the nerves and/or blood vessels, it might not be possible to save the arm or leg. In this case, amputation, or removal of all or part of the limb along with the cancer, may be the only option.

  • Limb-salvage (limb-sparing) surgery - The surgeon removes the entire tumor but not the nearby tendons, nerves, and blood vessels. The surgeon replaces the bone that was removed with a bone graft or internal prosthesis (endoprosthesis). This is a very complex operation and must be done by surgeons with special skills and experience.
  • Bone graft - The surgeon transplants a piece of bone to the site where the cancer was removed. The bone may come from the patient (autologous bone graft) or from someone else (allogeneic bone graft).
    • Endoprosthesis - An endoprosthesis is an artificial replacement for bone within the body that is made of metal or other materials. When they are implanted into growing children, they are designed to lengthen as the child grows; this sometimes, but not always, requires additional surgeries. Some “growing” prostheses have a tiny device that can lengthen the prosthesis whenever needed to make room for the child’s growth.
  • Amputation - The surgeon plans the operation so that the muscles and skin that are left form a cuff around the amputated bone. The cuff fits into the end of an artificial (prosthetic) arm or leg.
    • Reconstructive surgery in the leg - Sometimes, if the leg is amputated at midthigh, the lower leg and foot is rotated and attached to the thigh bone. This procedure is called rotationplasty. The ankle then serves as a knee joint. The patient then needs a prosthesis to extend the leg.
    • Reconstructive surgery in the arm - If the osteosarcoma is in the upper arm, the lower arm may be reattached after the tumor is removed so that the patient has a working arm, even though it is much shorter.
    • Reconstructive surgery in the jaw - If the osteosarcoma is in the lower jaw bone, the surgeon may remove the lower half of the jaw and replace it later with bones from other parts of the body.
If your osteosarcoma can be completely removed by surgery, you will probably be treated with chemotherapy for about 10 weeks to shrink the tumor before the surgery. After surgery, you will probably be treated with more chemotherapy (possibly the same drugs you took before surgery) to reduce the chance that the cancer will come back. This time, you will probably receive chemotherapy treatments for approximately 1 year. Although there is no specific survival benefit for preoperative as compared to postoperative chemotherapy, preoperative administration may permit a greater number of patients with extremity tumors to undergo limb-sparing procedures.
If your osteosarcoma cannot be completely removed by surgery, you will probably be treated with chemotherapy for about a year instead of having surgery.
The chemotherapy drugs that are most likely to be used include:
  • Adriamycin® (doxorubicin) - Doxorubicin hydrochloride belongs to the group of chemotherapy drugs known as anthracycline antibiotics. Doxorubicin stops the growth of cancer cells, causing them to die. This drug is given by a shot in a vein over about 15 minutes. The dose and how often you get the medicine depend on your size, your blood counts, how well your liver works, and the type of cancer you have.
  • Blenoxane® (bleomycin) - Bleomycin belongs to the group of chemotherapy drugs known as antibiotics. Bleomycin interferes with cell division, which destroys the cells. Bleomycin is given by a shot into a vein, either over 10 minutes or as a continuous infusion for 24 hours, or as a shot into the muscle or under the skin. The dose is based on your size.
  • Cytoxan® or Neosar® (cyclophosphamide) - Cyclophosphamide belongs to a group of chemotherapy drugs known as alkylating agents. It stops the growth of cancer cells, causing them to die. This drug can be given by mouth as a pill or liquid, or by a shot into a vein. The dose depends upon your size, your blood counts, and your type of cancer.
  • Ifex® (ifosfamide) - Ifosfamide belongs to a group of chemotherapy drugs known as alkylating agents. Ifosfamide stops cancer cells from growing, which kills them. Ifosfamide is given as an injection in a vein over 1 to 24 hours for a few days. The dose depends on your size, how well your kidneys are working, your blood counts, and the type of cancer being treated.
  • Paraplatin® (carboplatin) - Carboplatin is a platinum chemotherapy drug that belongs to a group of drugs known as alkylating agents. It stops cancer cells from growing, which kills them. Carboplatin is given as an injection in the vein over 15 to 60 minutes. The dose depends upon your size but may be lowered or not given if your blood counts are low.
  • Platinol® (cisplatin) - Cisplatin is a platinum compound chemotherapy drug that acts like an alkylating agent. It stops cancer cells from growing, which kills them. Cisplatin is given by an injection into the vein over at least 1 hour. Your dose depends upon the type of cancer you have, your size, and how well your kidneys work.
  • Rheumatrex® or Trexall™ (methotrexate) - Methotrexate belongs to a group of chemotherapy drugs known as antimetabolites. It prevents cells from making DNA and RNA, which stops the growth of cancer cells. Methotrexate is given as a pill by mouth, an injection in a vein for up to 20 minutes, or an injection into a muscle. The dose depends on your size, the type of cancer you have, your blood counts, and how well your kidneys work.
  • VePesid® or Etopophos® (etoposide) - Etoposide belongs to the class of chemotherapy drugs known as plant alkaloids. It stops cells from dividing, which kills them. Etoposide can be given by an injection in a vein over 30 to 60 minutes, or at higher doses over 1 to 4 hours. Etoposide can also be given by mouth as a capsule. The dose depends on your size, your blood counts, and the type of cancer being treated.  

    Usually, several chemotherapy drugs are given at the same time. The most common combinations are:
  • Doxorubicin and cisplatin
  • Dactinomycin, bleomycin, and cyclophosphamide
  • Ifosfamide and etoposide
If your osteosarcoma cannot be completely removed by surgery, you might be treated with radiation in addition to chemotherapy. The radiation treatment is most likely to be external beam radiation therapy, but bone-seeking isotopes and internal radiation therapy are also options.

  • External beam radiation therapy (EBRT) - Radiation from a high-energy x-ray machine (linear accelerator) outside the body is focused on the cancer cells. EBRT can harm both the cancer cells and nearby healthy tissue. Most people are treated with EBRT for a few minutes 5 days a week for several weeks as an outpatient. EBRT is the most common kind of radiation therapy for osteosarcoma.
  • Bone-seeking isotopes - A bone-seeking radioactive chemical, such as samarium-153, is injected into a vein. The chemical attaches to active areas of bone formation, including osteosarcoma. This treatment is useful for treating advanced disease and reducing pain.
  • Internal radiation therapy (brachytherapy or interstitial radiation therapy) - Small pellets (or “seeds”) that contain radioactive materials are placed in your body in or near the tumor. The radioactive pellets release their radiation slowly over time. Brachytherapy lets the doctor use a higher dose of radiation than EBRT.

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