They were randomly assigned ( 1:1 ) by the minimisation method to either doxorubicin ( 75 mg/m ( 2 ) by intravenous bolus on day 1 or 72 h continuous intravenous infusion ) or intensified doxorubicin ( 75 mg/m ( 2 ) ; 25 mg/m ( 2 ) per day , days 1-3 ) plus ifosfamide ( 10 g/m ( 2 ) over 4 days with mesna and pegfilgrastim ) as first-line treatment .