ABSTRACT
The WHO Classification of Tumors, Thoracic Tumors, 5th edition, has outlined the use of TTF-1 and ΔNP63/P40 to discriminate between adenocarcinoma and squamous cell carcinoma. In 2015, the first description of a rare non-small cell lung carcinoma featuring co-expression of glandular and squamous differentiation within most of the same individual tumor cells was reported on, with ultrastructural and molecular demonstration of such a biphenotypic differentiation. We herein describe an additional case of this rare tumor entity, which is confirmed to be an aggressive neoplasm despite potential targets of therapy.
Subject(s)
Adenocarcinoma , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Lung Neoplasms/diagnosis , Lung Neoplasms/pathology , Carcinoma, Non-Small-Cell Lung/diagnosis , Carcinoma, Non-Small-Cell Lung/pathology , Adenocarcinoma/diagnosis , Adenocarcinoma/pathology , Lung/pathology , Prognosis , Biomarkers, TumorABSTRACT
ROS1 tyrosine kinase inhibitors (TKIs) were found to provide a substantial clinical benefit for patients with advanced ROS1-positive (ROS1+) NSCLC. Nevertheless, TKI resistance inevitably develops with different mechanisms, preventing prolonged responses. For this reason, next-generation compounds are under clinical development. ROS1 F2004 substitutions have been previously detected on circulating tumor DNA of patients progressing to entrectinib. Hereby, we report the case of a patient with ROS1+ NSCLC in which F2004V-acquired mutation was detected on a site of disease progression, after entrectinib and crizotinib failure. A subsequent treatment with next-generation TKI repotrectinib led to disease response, providing the first clinical evidence of activity of repotrectinib against F2004V resistance mutation.