Next Generation Sequencing of Stage IV Squamous Cell Lung Cancers Reveals an Association of PI3K Aberrations and Evidence of Clonal Heterogeneity in Patients with Brain Metastases. Homo sapiens

Putative oncogenic pathways in squamous cell lung cancer have been recently characterized, although their biologic repercussions in patients is largely unknown. This study sought to discover potential clinical manifestations of major pathways in squamous cell lung cancer, particularly the PI3K pathway. Two key findings emerged: patients with stage IV squamous cell lung cancer whose tumors harbored upstream PI3K aberrations had significantly worse survival and a higher burden of metastatic disease. In addition, brain metastases were significantly more common in these patients than in others. Paired lung primary/brain metastasis genotyping, including RNA sequencing and whole exome sequencing, uncovered a high degree of genetic heterogeneity between lung/brain pairs, and identified potential regulators of the metastatic process to brain.