During this study, all study participants whose tumor(s) can be taken out with surgery will be offered routine surgery to remove the tumor(s). After surgery, if the doctor believes the tumor(s) have responded well enough, the standard treatment combination is again doxorubicin, cisplatin, and methotrexate. If the tumor(s) have not responded well enough, however, the standard treatment combination is methotrexate and ifosfamide.