Prognostic role of HER2 expression in bladder cancer: a systematic review and meta-analysis

The prognostic role of human epidermal growth factor receptor 2 (HER2) in bladder cancer (BCa) remains controversial. Thus, we conducted a meta-analysis to assess the prognostic significance of HER2 for patients with BCa. Systematically computerised searching in PubMed, Scopus database, Embase and Cochrane Library Database was conducted. Published studies comparing the prognosis in patients with BCa stratified by HER2 status were included, and relationships between HER2 positivity and gender, stage, grade, lymph node metastasis and survival were analysed. Nine studies with 2,242 eligible patients were identified. HER2 expression was significantly correlated with poor disease-specific survival [pooled hazard ratio (HR) 2.00; 95 % confidence interval (CI) 1.22-3.29; P = 0.006] and disease-free survival (pooled HR 1.68; 95 % CI 1.33-2.14; P < 0.0001) of patients with BCa. The positive rates of HER2 ranged from 27.8 to 85.2 % with a pooled positive rate of 41.2 % (1,006/2,442). HER2 expression was significantly associated with tumour grade [high grade vs. low grade: odds ratio (OR) 4.08; 95 % CI 1.29-12.93] and lymph node metastasis (positive vs. negative: OR 1.71; 95 % CI 1.07-2.75). This meta-analysis indicated that HER2 expression is associated with poor prognosis. Thus, HER2 could serve as a useful biomarker for clinical prediction.