ALK and non-small cell lung carcinoma: Alterations in anaplastic lymphoma kinase, v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2, mixed-lineage leukemia 4, phosphatidylinositol 3-kinase complex, and topoisomerase II alpha were less frequently detected in oligometastatic compared to polymetastatic NSCLC, suggesting that stage IV tumors harboring those mutations are more likely to have polymetastatic behavior.