One of the major weaknesses of these trials is the unselected mixed pool of stage III patients (stage III A and B, lymph node status N0 to N2, squamous and non-squamous histology etc.). A broad variety of studies have shown that a certain subset of patients with NSCLC (e.g. cancers with adenocarcinoma histology, multilevel nodal involvement) are at highest risk for brain metastases. Furthermore, the risk for brain metastases appears to be specifically higher in younger patients (age <60 years), although this collective commonly undergoes more frequently chemotherapy and/or more aggressive regimens than elderly patients.