Erlotinib maintenance showed a favourable ICER in patients with PS = 0 ( 94,908 / QALY ) , in patients with adenocarcinoma ( 97,160 / QALY ) and in patient with objective response to induction ( 101,186 / QALY ) , but it is not cost-effective in patients with PS = 1 , in patients with non-adenocarcinoma or with stable disease after induction chemotherapy .