Excellent platinum dependent response to chemotherapy after relapse under TKI treatment in NSCLC with sensitizing EGFR mutations and no detectable resistance mutations: three case studies.

First-line tyrosine-kinase inhibitor (TKI) treatment is the current standard for patients with metastasized non-small cell lung cancer (NSCLC) and sensitizing epidermal growth factor receptor (EGFR) mutations. Despite good initial responses, patients treated with TKIs relapse after an average of 12 months. About half of them develop known resistance mechanisms and therefore are qualified for further targeted therapies. However, many patients still have to be treated with standard chemotherapeutic regimens. In this case series we describe three patients with similar progression patterns under TKI treatment in the absence of treatable resistance mechanisms and excellent platinum dependent response to chemotherapy and review the current literature focusing on effectiveness of standard chemotherapy in this cohort. 2019 AME Case Reports. All rights reserved.