EGFR and small cell lung carcinoma: Although SCLC transformation has been considered to be the most common histologic transformation in EGFR-mutant NSCLCs in patients with disease progression during treatment with an earlier-generation EGFR TKI, [7] SCC transformation emerged as a potentially more common (15%) histologic transformation in front-line osimertinib-treated patients in a small cohort of patients with limited follow-up [18].