case_images: PMC8445031_01
case_images: Baseline data: (A) Positron emission tomography-computed tomography (PET-CT) image. (B) Representative histopathological image of the tumor (H&E staining). (C) Next-generation sequencing showed an L861Q mutation in the epidermal factor receptor exon 21.
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case_images: f1
case_images: Positron emission tomography-computed tomography (PET-CT) revealed a fluoro-2-deoxy-d-glucose (FDG)-positive lesion in the left middle lung lobe and metastases in multiple bones (Figure 1A). TTF-1 staining (Figure 1B). To identify potentially actionable mutations of the patient, paired NGS-based genetic testing of 1,021 cancer-related genes was performed with both circulating free DNA from plasma and DNA extracted from the leukocytes (Geneplus-Beijing Ltd., Beijing, China). EGFR L861Q mutations (allelic fraction, AF=6.1%) in exon 21 were identified by next-generation sequencing (NGS) of the plasma, with concurrent TP53 N239S mutation in exon 7 and RB1 mutations (Figure 1C).
case_images: Representative computed tomography images at various points (A) and mutation analysis of the patient's plasma (B) before and after osimertinib treatment.
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case_images: He experienced progressive disease of the right frontal lung lobe, subcarinal lymph node, and brain metastases after a progression-free survival (PFS) of 15.0 months (Figure 2A). The AF of the L861Q mutation increased to 73.2%, with TP53 and RB1 mutations and absence of EGFR T790M (Figure 2B).
case_images: Schematic of the course of disease management, showing different treatment regimens prescribed and the results of the mutation analyses.
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case_images: f3
case_images: The last follow-up was in November 2020, after which the patient passed away, with an overall survival of 19 months (Figure 3).