Human epidermal growth factor receptor 2: a significant indicator for predicting progression in non-muscle-invasive bladder cancer especially in high-risk groups.

Purpose: Current pathological and clinical parameters provide important prognostic information. However, they are still limitations for predicting the true malignant potential of a specific cancer. The aim of this study was to validate the predicting role of HER-2 expression and demonstrated that combination of the high-risk factors with HER-2 expression is more valuable for determining which non-muscle-invasive bladder cancer (NMIBC) is more aggressive.

Materials And Methods: In total, 238 patients treated by transurethral resection of the bladder tumor were histopathologically confirmed to be NMIBC. Two experienced uropathologists re-reviewed the slides. HER-2 expression was evaluated by immunohistochemistry and scored for intensity and area of staining. The association of HER-2 staining with tumor recurrence and progression was evaluated by univariate and multivariate analyses and Kaplan-Meier survival curves.

Results: In multivariable analyses, HER-2 expression was an independent risk factor for predicting tumor progression (HR 2.64, p = 0.024). Combining the EORTC risk scores with HER-2 expression status led to more accurate prediction of progression, especially in patients with intermediate- and high-risk EORTC scores (p < 0.0001, log-rank test).

Conclusions: HER-2 positivity is prognostic for predicting progression to muscle invasion in NMIBC. Combination of the high-risk factors with HER-2 expression is more valuable for determining which NMIBC is more aggressive.