HER2 overexpression rare in prostate cancer but linked to higher Gleason score and stage

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The Prostate Published June 1, 2026 Medically reviewed June 1, 2026 Study authors: Luk Jacky T F, Lin Alex H, Cheung Esther K C, Meçani Renald, Muka Taulant, Nano Jana, Ng Joanna K M,… PubMed ↗ DOI ↗ By Dr. Lars van Dijk, PhD · Surgical, Procedural & Diagnostic

Key Takeaway

Consider that HER2 overexpression is rare in prostate cancer but associated with higher Gleason score and advanced stage.

This systematic review and meta-analysis evaluated the prevalence of HER2 expression in prostate carcinoma and its association with clinicopathological features, pooling data from 1258 cases across included studies. The primary outcome was the prevalence of HER2 expression, with secondary outcomes including associations with Gleason score, disease stage, biopsy site, patient age, and PSA level.

Key findings: HER2 Score 3 overexpression was found in 4.9% of cases (95% CI 3.0%-7.2%; 70 of 669 cases), while HER2 non-negative expression (Scores 1-3) was present in 42.0% (95% CI 29.0%-55.6%). Higher Gleason score (OR 0.061, 95% CI 0.010-0.359, p<0.001) and advanced disease stage (OR 0.063, 95% CI 0.016-0.252, p<0.001) were significantly associated with HER2 overexpression. Biopsies from metastatic sites also favored overexpression (OR >100, p<0.001). No significant associations were found with patient age or PSA level.

The authors note limitations including high heterogeneity (I²=91.63%, p=0.043) and moderate publication bias risk (LFK index 1.93, p=0.054). These are observational associations only and do not imply clinical efficacy of HER2-targeting agents in prostate cancer.

Practice relevance: While HER2 overexpression is rare, nearly half of prostate carcinomas show some HER2 expression, and overexpression is more likely in aggressive disease. This may inform future research on HER2-directed therapies in selected patients.

Study Details

Study typeMeta analysis

EvidenceLevel 1

PublishedJun 2026

PMID42018554

View Original Abstract ↓

INTRODUCTION: The clinical relevance of HER2 expression profile in solid cancers has expanded with the evolving landscape of HER2 targeting agents. This systematic review and meta-analysis aim to detail the prevalence of HER (over)expression in prostate cancer and identify patient/disease subgroups with enriched HER2 overexpression. METHODS: Literature searches of five databases were performed. HER2 scores with cross-tabulation of clinicopathological parameters were extracted for pooled prevalence and odds ratio analyses. Study quality, heterogeneity, and publication bias were assessed by the CASP checklist, I index, and LFK index. RESULTS: In total, 16 studies were included with 1258 cases. There were 669 (53.18%), 269 (21.38%), 250 (19.87%), and 70 (5.56%) of HER2 Scores 0/1/2/3, respectively. Pooled analysis indicated a prevalence of 4.9% (95% CI 3.0%-7.2%) for HER2 Score 3 and 42.0% (95% CI 29.0%-55.6%) for HER2 non-negative (Scores 1-3). Subgroup analysis comparing HER2 negative (0, 1) and HER2 overexpression (3) indicated higher Gleason score (OR = 0.061, 95% CI: 0.010-0.359, p < 0.001), higher disease stage (OR = 0.063, 95% CI: 0.016-0.252, p < 0.001) and biopsies from metastatic site (OR: > 100, 95% C.I.: > 100-> 100, p < 0.001) favoring HER overexpression, without significant differences for patient age or prostate-specific antigen (PSA) level. I was 91.63% with meta-regression analysis showing study quality as a source of heterogeneity (p = 0.043). LFK index was 1.93 (moderate publication bias risk, p = 0.054). CONCLUSIONS: HER2 overexpression is rare in prostatic carcinomas but nearly half show HER2 expression of Score 1 or above. Cases with higher Gleason score and advanced disease stage are more likely to overexpress HER2.