Patients were randomly assigned ( 1:1 ) to receive either six cycles ( three concomitant to radiotherapy ) of oxaliplatin 85 mg/m ( 2 ) , leucovorin 200 mg/m ( 2 ) , bolus fluorouracil 400 mg/m ( 2 ) , and infusional fluorouracil 1600 mg/m ( 2 ) ( FOLFOX ) over 46 h , or four cycles ( two concomitant to radiotherapy ) of fluorouracil 1000 mg/m ( 2 ) per day for 4 days and cisplatin 75 mg/m ( 2 ) on day 1 .