HER2 discordance between primary and metastatic gastric cancer: a systematic review and meta-analysis.
Clin Transl OncolMay 12, 2026 (epub)
Francisco Cezar Aquino Moraes, Luis Henrique Rios Moreira Rego, Thiago Gorayeb Rebelo et al.
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In 30 seconds
This systematic review and meta-analysis evaluated HER2 status discordance between primary and metastatic gastric cancer in 3,515 patients across 20 studies. The analysis found that HER2-positive expression was 13% in primary tumors and 18% in metastatic lesions, highlighting significant variability in HER2 positivity across different metastatic sites.
Key findings
- HER2-positive expression in primary gastric tumors was 13% (95% CI: 12-15%).
- In metastatic sites, the overall pooled proportion of HER2-positive lesions was 18% (95% CI: 16-20%).
- HER2 positivity varied by metastatic site: 38% in lung, 31% in liver, 19% in lymph nodes, and 7% in peritoneum.
- HER2-negative metastases accounted for 82% overall (95% CI: 80-84%).
Why it matters
Understanding HER2 discordance between primary and metastatic gastric cancer is crucial for optimizing treatment strategies. Accurate HER2 status assessment can guide targeted therapies, potentially improving patient outcomes.