label: Small Cell Lung Carcinoma Transformation
label_lc: small cell lung carcinoma transformation
description: "A term that usually refers to the histological transformation of EGFR mutation-positive lung non-small cell carcinoma to small cell carcinoma in response to treatment with tyrosine kinase inhibitors, resulting in resistance to first-line tyrosine kinase inhibitors. It may also refer to rare cases of lung adenocarcinoma carrying KRAS G12C mutation that are transformed into small cell carcinoma before treatment."