A challenging case of stage IV EGFR-mutant lung cancer with histologic transformation and multiple resistance mechanisms

This clinical case presents a patient with NSCLC who experienced on-target resistant mutations and tumor cell transformation from adenocarcinoma to large cell neuroendocrine and small cell carcinoma. Our patient was successfully treated with a combination of targeted therapy, immunotherapy and chemotherapy based on genetic and histologic changes that occurred in a period of five years.