ALK and lung adenocarcinoma: Furthermore, Halpenny et al. reported that ALK-positive lung adenocarcinomas are more likely to exhibit multifocal thoracic lymphadenopathy, compared to EGFR-positive lung adenocarcinomas, although they only included a relatively small number of ALK-positive patients (8 cases of stage IIIB and 18 cases of stage IV) [19].