•Aneurysmal bone cyst

•Benign and aggressive osteoblastoma

•Chondrosarcoma

•Malignant fibrous histiocytoma

•Giant-cell tumor

•Metastatic carcinoma (extremely rare in childhood)

•Langerhans cell histiocytosis

•Infection

13.11Treatment

•Management ideally done using national or international clinical trials. Large international studies are necessary to increase quality of clinical research, including an adequate sample size according to biometric analyses

•Combined-modality treatment is essential

•Neoadjuvant chemotherapy with standardized evaluation of chemotherapy response of the tumor at the time of definitive surgery, followed by risk stratification and postsurgical risk-adapted therapy

•Surgery: goal is a wide resection. Limb-saving surgery with allograft or prosthesis is commonly able to be accomplished. In situations of unclear surgical resection, and in disease that responds poorly to chemotherapy responders, amputation may be considered

•Adjuvant postsurgical chemotherapy according to tumor response to chemother- apy and according to a standardized risk stratification is important in improving outcome

•High-dose chemotherapy with autologous stem-cell transplantation has not been proven to be of value

•Osteosarcoma is relatively radioresistant

•Liposomal muramyl tripeptide phosphatidyl ethanolamine (L-MTP-PE, mifamurtide), acts probably through immunomodulation. The significance in the management of patients with osteosarcoma is unclear. An evaluation of a potential survival advantage due to this drug needs further, prospective randomized clinical trials.

13.11.1 Treatment of Relapsed Disease

•Prognosis is poor; 5-year post-relapse survival is less than 30%

•Complete surgical resections of primary and/or metastatic disease are important prognostic factors

13.12Prognosis

•Results from the German Cooperative Osteosarcoma Study Group (COSS) include the following:

•Five-year overall survival is approximately 65%

•Five-year overall survival in patients without detectable metastasis at diagnosis is approximately 70%

•Five-year overall survival in patients with detectable metastasis at diagnosis is approximately 30%. Favorable prognostic factors include single metastasis and complete surgical resection of disease

•Patients who respond well to neoadjuvant chemotherapy have a significantly better prognosis than poor responders

•Other important prognostic factors:

–Location of primary tumor (osteosarcoma of extremities has a better prognosis than other locations), tumor size, surgical result (patients with incomplete resection have a worse prognosis)

13.13 Complications

•According to location of the lesion

•Secondary malignancy

•Psychological complications (related to diagnosis, location, therapy, body image, and functional limitations)

•Social problems (costs, school, professional guidance, social contacts, insurability)