[Neoadjuvant therapy for localized osteosarcoma of extremities. Results from the Cooperative osteosarcoma study group...

Owing to twenty years of multicentric interdisciplinary cooperation, the COSS group has been able to collect data on a large group of osteosarcoma patients treated by neoadjuvant therapy. This paper reviews results achieved in patients with localized extremity tumors.

Registration into a completed neoadjuvant COSS-Study. Histologically confirmed, primary, localized, high-grade, central osteosarcoma of an extremity; age < 40 years; no pretreatment; interval diagnosis to chemotherapy < or = 3 weeks; no severe comorbidity. Chemotherapy: HD-methotrexate +/- doxorubicin +/- cisplatin +/- ifosfamide +/- BCD. Scheduled local therapy: Surgery.

925 evaluable patients from 101 institutions. Median age 15 years, m:f 1.4:1. Primary site: femur 510, tibia 251, humerus 100, fibula 51, other 13. Tumor-size < 1/3 of the involved bone 616, > or = 1/3 304. Definitive surgery in 903/925 cases, 443 limb salvage procedures. Good response (> 90% necrosis) in 469/806 (58.2%) evaluated tumors. Median follow-up for surviving patients: 5.42 years. Actuarial survival after 5 and 10 years: 72.5% (95%-CI 69.3-75.7) and 66.3% (62.5-70.0), relapse-free 62.1% (58.7-65.4) and 59.4% (55.8-63.0). 683/925 alive (601 first remission), 242 deceased (212 tumor progression, 30 other causes). 66.2% (97.3%) of all relapses within 2 (5) years. Prognosis correlates with tumor-size (< vs. > or = 1/3: 69.9% vs. 58.3% at 10 years) and -site (tibia: 74.2%, humerus: 54.5%) and -response (good vs. poor: 78.2% vs. 52.5%) (all p < 0.01). Actuarial 10-year survival by response grading I-VI according to Salzer-Kuntschik 80.9%, 82.8%, 71.1%, 60.7%, 47.7%, 27.3%. COSS-studies with preoperative 4-drug therapy more efficacious than less aggressive protocols. No impact of doxorubicin scheduling (sequential: rapid vs. 48 h-continuous infusion) or cisplatin scheduling (randomized: 5 h vs. 72 h-infusion) on prognosis detected.

Intensive multiagent chemotherapy and delayed surgery for localized extremity osteosarcoma led to excellent oncologic results in the COSS-studies. Tumor-size, -site, and -response as well as the intensity of upfront chemotherapy correlated with outcome. Giving doxorubicin and cisplatin by continuous infusions did not result in discernible prognostic disadvantages.