J Med Cases

Journal of Medical Cases, ISSN 1923-4155 print, 1923-4163 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Med Cases and Elmer Press Inc

Journal website https://jmc.elmerpub.com

Case Report

Volume 17, Number 12, December 2026, pages 691-697

Sequential Precision Therapy Strategy for ARID1A/PIK3CA/ATM-Altered Gallbladder Cancer: A Case Report of Prolonged Stable Disease

Figures

↓ Figure 1. Evidence blocks supporting the clinical significance of the biomarkers (a–c) uncovered by the initial comprehensive genomic profiling and the measures reflected in the evidence blocks (d). Evidence blocks are filled in a similar manner to that of NCCN evidence blocks [20]. NCCN: National Comprehensive Cancer Network.

↓ Figure 2. Treatment timeline. Alterations targeted at each line of sequential precision therapy are shown in red. 1L: first line; 2L: second line; CMP: comprehensive molecular profiling.

Table

↓ **Table 1.** A Summary of Alterations Uncovered Following Initial (Left) and Subsequent (Right) Genomic Testing
Gene	Variant	VAF	Effect	Origin
^aMatching alterations observed in both analyses. ^bBased on variant allele frequency; confirmatory testing of non-tumor DNA was not performed. TMB: tumor mutational burden; VAF: variant allele frequency; VUS: variant of unknown significance.
Initial testing (primary tumor)
PIK3CA^a	p.E542K	26%	Activating	Somatic
ATM^a	p.E1978Ter	28%	Deleterious	Potentially germline^b
ARID1A	p.A1466fs	20%	Deleterious	Somatic
TMB: 4.2 mutation/Mb
Subsequent testing (metastatic lesion)
PIK3CA^a	p.E542K	35%	Activating	Somatic
ATM^a	p.E1978Ter	45%	Deleterious	Potentially germline^b
ATM	p.R1204Ter	22%	Deleterious	Somatic
BRCA2	p.M2935I	20%	VUS	Somatic
SPINK1	p.N34S	36%	Risk factor	Potentially germline^b
TMB: 2.6 mutation/Mb