Surgery is an integral part of treatment for patients with localized osteosarcoma as well as select patients with metastatic or recurrent osteosarcoma. Treatment of osteosarcoma without surgery results in significantly lower cure, tumor-free survival, and overall survival rates. Researchers from the MD Anderson Cancer Center have documented the necessity of surgery in osteosarcoma treatment.1 Reconstructive surgery is also an important component of the overall management of osteosarcoma, requiring the skills of an orthopedic surgeon or other specialized surgeons.

Because osteosarcoma is a relatively rare cancer, treatment should be conducted in specialized medical centers. Medical centers specializing in osteosarcoma treatment have established a treatment protocol, or procedure, as a result of treating many patients with the same cancer. Also, specialty centers utilize an experienced multidisciplinary team in order to ensure that patients receive treatment, supportive care, and rehabilitation that will achieve optimal survival and quality of life. In the case of osteosarcoma, this team should be well-versed in treatment of cancers that occur during childhood and adolescence. Included in the multidisciplinary team are: a primary care physician, an orthopedic surgeon experienced in bone tumors, a pathologist, radiation oncologists, pediatric oncologists, rehabilitation specialists, pediatric nurse specialists, social workers, and others. The primary cooperative group evaluating osteosarcoma treatment in the US is the Children’s Cancer Study Group.

Surgery for Localized Osteosarcoma

Historically, a complete removal or amputation of the affected limb was the main treatment for patients with osteosarcoma. This approach resulted in the cure of approximately 20% of patients. With the advent of chemotherapy, limb preservation is now possible in over 80% of patients with localized osteosarcoma.

It is imperative that patients with proven or suspected osteosarcoma have an initial evaluation by an orthopedic oncologist familiar with the surgical management of this disease. This evaluation should be done prior to the initial biopsy, since an inappropriately performed biopsy may jeopardize a limb-sparing procedure. Limb-sparing surgery consists of local removal of the cancer, including wide margins of healthy tissue in order to ensure that most of the cancer was removed. Limb-sparing surgery after neoadjuvant chemotherapy is the most common approach to the treatment of patients with localized osteosarcoma.

Research suggests that this combination of treatment is also the most effective. A study of 202 patients treated for osteosarcoma showed that 49% of these patients lived 5 years or more. This study compared limb-sparing and survival rates from 3 different centers affiliated with the European Osteosarcoma Intergroup. Although patients who had undergone limb-sparing surgery did experience local recurrence of their cancer, 31% of these were cured with subsequent surgery.2

Surgery for Metastatic or Recurrent Osteosarcoma

For metastatic and recurrent osteosarcoma, initial surgery must remove as much of the primary tumor as possible, as well as all metastatic cancer that is operable. The lungs are the most common site of both metastases and recurrences of osteosarcoma after initial treatment. Lung metastases are usually removed by wedge resection, which removes a very small part of the lung and is used when the cancer has been diagnosed early and is only in one very small area. However, pneumonectomy, removal of an entire lung, may occasionally be required in order to remove all of the cancer. When cancer is present in both lungs, a separate incision is performed in each lung.

Complete removal of the cancer in the lungs is the most important factor for optimizing long-term survival. For patients with recurrent disease whose lung cancer is completely removed, 5-year survival rate is 20-40%. Patients with fewer nodules and only one lung involved do better than patients with multiple cancers and/or involvement of both lungs. A long interval between the primary diagnosis and the appearance of recurrent disease is also associated with better outcomes.

Due to the advent of adjuvant and neoadjuvant chemotherapy, survival rates for osteosarcoma that has metastasized or recurred in the lungs have greatly improved to 41%, compared to 0% in early studies. Chemotherapy is a systemic treatment that shrinks the primary cancer. Research suggests that chemotherapy treatment has made more cases operable. In a recent study, researchers at UCLA evaluated outcomes of 247 patients with pulmonary metastases from osteosarcoma. In the patients treated since the development of adjuvant and neoadjuvant chemotherapy, 82% underwent surgical removal of their metastases, a rate much higher than those patients treated before the development of adjuvant and neoadjuvant chemotherapy.3

Reconstructive Surgery

Limbs may be reconstructed after surgical removal of the primary osteosarcoma. There are a number of different reconstructive surgery procedures including bone grafts, rotationplasty, and prosthetics. Selection of treatment depends on the location and extent of the bone removed and the age of the patient, since some treatments are limited in young patients who are still growing.

Bone grafts: Bone grafts consist of transplanting a piece of bone to repair the site where the cancer was removed. Bone grafts are usually only used for localized cancer. There are two types of bone grafts: allogeneic, where the bone comes from another individual, and autologous, where the bone material comes from the patient. Since the body considers tissue from another individual as foreign, rejection of this tissue is a problem in allogeneic bone grafts. Rejection does not occur with autologous grafts because the bone tissue is the patient’s and not foreign. However, the utility of bone grafts are limited in young patients because their bones are still growing.

Autologous bone grafts can be very effective when the cancer can be removed, but some of the bone can be reimplanted. In this procedure, radiation is performed before reimplantation in order to eradicate the cancer from the bone. In one study, eight patients who had primary cancer in their long bones were treated with this procedure. Most of the patients had eradication of osteosarcoma without losing limb function.4

Prosthetics: Endoprostheses utilize artificial material to fill in for surgically removed bone, or functional joints to replace the amputated joint. Two studies conducted at UCLA have reported effective and durable results with this technique. In the first study, reconstruction with endoprostheses was used in 78 of 100 patients treated for localized osteosarcoma. Excellent results were reported in reconstruction of the upper leg near the knee.5 In the second study, 151 patients received endoprostheses for primary tumors involving bone. Modification of the prosthesis was necessary in 21 patients. Mechanical failure was the primary complication, which occurred in 15.9% of patients. However, local problems were usually managed without amputation and the prostheses proved durable, with 91% of patients surviving three years and 83% surviving five years.6

One problem with standard prostheses is that they do not expand to accommodate growing bones in young patients whose skeletons are not yet mature. Preliminary results with expandable endoprostheses appear promising and suggest that, with redesign, these may offer an alternative to amputation and rotationplasty in children with bone cancer. In one study, custom-expandable endoprostheses were used to treat 12 young patients with osteosarcoma or other bone tumors. Seven patients had a total of 11 expansions and one patient was lengthened with a revision-expandable prosthesis. Four patients did not need expansion. Overall function rating was good to excellent in 58%, fair in 25%, and poor in 17%. There was a high rate of expansion mechanism failure, necessitating redesign of the prostheses.7

Strategies to Improve Treatment:

The development of more effective cancer treatments requires that new and innovative therapies be evaluated with cancer patients. Clinical trials are studies that evaluate the effectiveness of new drugs or treatment strategies. Future progress in the surgical treatment of osteosarcoma will result from the continued evaluation of new treatments in clinical trials. Participation in a clinical trial may offer patients access to better treatments and advance the existing knowledge about treatment of this cancer. Patients who are interested in participating in a clinical trial should discuss the risks and benefits of clinical trials with their physician. Areas of active exploration to improve the surgical treatment of osteosarcoma include the following:

Reconstructive Surgery: Most of the surgical research in patients with osteosarcoma is in reconstructive surgery procedures. These procedures can dramatically affect quality of life. Patients and families will need to carefully review the many options and the latest prostheses available. It is important for patients and families to seek educational materials that help them understand these complicated procedures before selecting a treatment.

References

---