Overview

A 70-gene gastric cancer panel that reports targeted variants, chemotherapy-context genes, and mismatch-repair status sits at the intersection of solid-tumor profiling and gastrointestinal-specific care. Microsatellite instability and mismatch-repair deficiency are established biomarkers across tumor types, and their inclusion in a gastric panel supports both therapy selection and the broader identification of hereditary cancer risk. For laboratories, the regulatory task is to deliver these results under a quality framework while clearly stating intended use, because MSI-high findings can have implications beyond the immediate treatment decision and may prompt genetic counseling referral. Gastric cancer is also a priority site for immune therapy in MSI-high disease, so reporting mismatch-repair status aligns the panel with a treatment pathway that is increasingly standardized rather than experimental.

Biomarkers the Panel Reports

Beyond the targeted and chemotherapy-context genes, the gastric panel reports microsatellite and mismatch-repair status, which flag tumors likely to respond to immune checkpoint inhibition. HER2 assessment also remains central in gastric cancer and is typically confirmed by immunohistochemistry with in-situ hybridization reflex, so a sequencing-based panel complements rather than replaces that workflow. Reporting these markers together gives oncologists a consolidated view, but each must be released with the method and cutoff the lab validated, since regulatory expectations differ between a sequencing-derived MSI call and a pathology-read HER2 result that follows a separate standard. Because gastric tumors can show heterogeneity, the panel's broad variant set improves the odds of catching a targetable alteration in a tumor where a narrower assay might return only unactionable findings.

Compliance and Reporting Standards

Quality frameworks such as CAP, CLIA, or ISO 15189 apply to the sequencing portion, and any MSI or MMR result that suggests hereditary predisposition should be reported with appropriate language and referral guidance. Buyers should verify the lab's validation for microsatellite calling and its policy on ambiguous results, because borderline calls need a defined path rather than silence. Cross-border distribution adds another layer: gastric cancer testing intended for multiple markets must align with each region's rules on companion claims and on how germline-risk information is handled. A structured report naming the assay, method, and every cutoff keeps the panel defensible during audit and useful at the tumor board.

FAQ

Q: Does the panel replace HER2 testing in gastric cancer? A: No. HER2 is usually confirmed by immunohistochemistry with in-situ hybridization reflex; the panel complements that workflow with sequencing data.

Q: Why include MSI and MMR in a gastric panel? A: Microsatellite instability-high status is an actionable biomarker and can also signal hereditary cancer risk, making it clinically important to report.

Q: Which quality standards should the lab meet? A: CAP, CLIA, or ISO 15189 recognition applies to the sequencing portion, with validated methods required for every reported biomarker.