case_images: PMC10885695_01
case_images: PMC10885695_02
case_images: Molecular and clinical response to anti-HER2 therapy. Changes in mutations identified and variant allele fraction in Patient 17 as identified by cfDNA analysis along with corresponding systemic therapy and imaging results. The CA19-9 levels for Patient 17 over time corresponding to the systemic therapy and molecular results are also shown. Imaging shows CT scans at initation of FOLFOX (A), discontinuation of FOLOX (B), and three months after trastuzumab monotherapy (C).
case_images: fonc-14-1339302-g003.jpg
case_images: PMC10885695_02_fonc-14-1339302-g003.jpg
case_images: f3
case_images: TP53 E285K at 0.1% VAF, and a BRCA1 variant of uncertain significance (VUS) at 0.9% VAF (Figure 3). The patient was initiated on FOLFOX, and trastuzumab was added soon afterward. The patient experienced clinical improvement and significant decline in CA19-9 (1,847 to 22 U/mL) over a four-month period (Figure 3). Only VUS and synonymous variants were detected on a repeat liquid biopsy, with a maxVAF of 0.7% (Figure 3). A final cfDNA test taken approximately one year after the previous test demonstrated the emergence of KRAS G12R at 0.3% VAF, BRCA2 L1522fs at 0.3% VAF, TP53 R196* at 0.2% VAF, and TP53 E285K at 0.1% VAF, with the ERBB2 amplification still not detected (Figure 3).