Patients with confirmed progressive disease following the first-line treatment with a gemcitabine-based regimen were randomised to receive either S-1 ( 80/100/120mgday ( -1 ) based on body surface area ( BSA ) , orally , days 1-28 , every 6 weeks ) or SOX ( S-1 80/100/120mgday ( -1 ) based on BSA , orally , days 1-14 , plus oxaliplatin 100mgm ( -2 ) , intravenously , day 1 , every 3 weeks ) .