case_images: PMC9304692_01
case_images: Hematoxylin-Eosin staining (A) and immunohistochemical staining of HER2 expression (B).
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case_images: PMC9304692_01_fonc-12-940263-g001.jpg
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case_images: IV,  Figure 1A ). HER2 positive (3+,  Figure 1B ). In addition, laboratory examinations revealed elevations in the levels of carbohydrate antigen 19-9 (CA19-9; 17463 U/ml), carbohydrate antigen 724 (CA724; 415.5 U/ml) and carcinoembryonic antigen (CEA; 50.41 ng/ml). He underwent 6 cycles of combination therapy composed of trastuzumab plus oxaliplatin and paclitaxel.
case_images: Computed tomography during treatment (A), blood tumor antigen changes (B), and timeline of the clinical course in this patient (C).
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case_images: PMC9304692_01_fonc-12-940263-g002.jpg
case_images: f2
case_images: Liver metastatic lesions (left lobe of liver, 2.66x2.12 cm; right lobe of liver, 2.59x1.56 cm) and hilar lymph node (1.24x0.97 cm) were shrunk, so that the efficacy was assessed as partial response (PR) according to iRECIST criteria ( Figure 2A ), followed by maintenance therapy with trastuzumab. After 4 cycles, although no abnormalities were observed in CEA, CA19-9, or CA724, CT showed spleen metastasis (1.34x1.23 cm) and brain metastasis (2.06x1.60 cm), with the efficacy defined as progressive disease (PD) ( Figure 2A ). However, CA724 (27.6 U/ml) was significantly elevated ( Figure 2B ). The efficacy was evaluated as stable disease (SD) ( Figure 2A ). April 27, 2021. At a recent re-examination, CT showed an increased left lobe of liver mass (3.23x1.71 cm) with effect assessed as PD ( Figure 2A ). Eventually second-line treatment of PFS of up to 20 months was given ( Figure 2C ).