Figure 3. Changes of driver genes in EGFR/ALK-coexisting patient treated with crizotinib.

A. Pre-crizotinib histology was adenocarcinoma (original magnification×200), and genetic profiles showed EGFR exon 19 deletion and exon 20 T790M mutation detected by DNA sequencing, as well as positive ALK rearrangement detected by FISH B. After resistance to crizotinib, both the histology (original magnification×200) and EGFR mutation were the same as the baseline, but ALK rearrangement was negative. ALK, anaplastic lymphoma kinase. EGFR, epidermal growth factor. DEL, deletion.