S0423 Pemetrexed Disodium in Treating Patients With Recurrent and Unresectable or Metastatic Chondrosarcoma

OBJECTIVES: Primary * Determine the response rate (confirmed and unconfirmed complete response and partial response) in patients with recurrent and unresectable or metastatic chondrosarcoma treated with pemetrexed disodium. Secondary * Determine the toxicity of this drug in these patients. * Correlate, preliminarily, response rates with deletions of methylthioadenosine phosphorylase (MTAP), as analyzed by fluorescence in-situ hybridization (FISH), in patients treated with this drug. OUTLINE: This is a multicenter study. Patients are stratified according to prior chemotherapy (yes vs no). Patients receive pemetrexed disodium IV over 10 minutes on day 1. Courses repeat every 21 days\* in the absence of disease progression or unacceptable toxicity. Beginning 7 days before the first dose of pemetrexed disodium and continuing until 21 days after the completion of pemetrexed disodium, patients receive cyanocobalamin (vitamin B\_12) intramuscularly once every 63 days and oral folic acid once daily. NOTE: \*The duration of course 1 is 28 days; the duration of all subsequent courses is 21 days. Patients achieving a complete response (CR) receive 2 additional courses beyond CR. Patients achieving a confirmed partial response (PR) that is resectable, proceed to surgical resection and then receive 2 additional courses of therapy after recovering from surgery. Patients achieving a confirmed PR that is not resectable continue treatment in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed every 3 months until disease progression and then every 6 months for up to 5 years. PROJECTED ACCRUAL: A total of 40-75 patients (20-40 in the previously treated stratum and 20-35 in the previously untreated stratum) will be accrued for this study within 20-37.5 months.