This study is a multicenter, randomized, open label, phase II study. Patients will be randomized to either lapatinib plus vinorelbine (LV) arm or vinorelbine alone (V) arm, if they are satisfied by inclusion and exclusion criteria. The stratification factors are followings: 1) visceral metastasis vs. others, 2) previous response to lapatinib treatment, complete response(CR)+partial response(PR) vs. stable disease(SD)≥ 12wks.