231P - Meta-analysis of HER3 expression and prognosis in solid tumors

Date 30 September 2012
Event ESMO Congress 2012
Session Poster presentation II
Topics Translational Research
Presenter Alberto Ocana
Authors A. Ocana1, F. Vera Badillo2, B. Seruga3, A. Pandiella4, E. Amir2
  • 1Medical Oncology, Albacete University Hospital, Albacete/ES
  • 2Medical Oncology, Princess Margaret Hospital, Toronto/CA
  • 3Sector Of Medical Oncology, Institute of Oncology, Ljubljana/SI
  • 4Salamanca Cancer Research Center, CIC-CSIC, Salamanca/ES

Abstract

Introduction

Aberrant activation of various ErbB receptors has been linked with malignant transformation. HER3 is an ErbB family member that can dimerize with other ErbB receptors such as HER2 and can modulate the transmission of oncogenic stimuli. The prognostic role of HER3 is not clear, but numerous agents against HER3 are currently in clinical development. Here we present a meta-analysis of studies evaluating the prognostic impact of HER3 expression.

Material and methods

Pubmed was searched for studies evaluating expression of HER3 (as measured by immunohistochemistry-IHC) and overall survival (OS) in solid tumors. Published data were extracted and computed into odds ratios (ORs) for death at 3 and 5 years. Subgroup analyses were performed to evaluate the association of HER3 with overall survival in different tumor types. Data were pooled using generic inverse variance and random-effect modeling.

Results

Eleven studies were eligible for analysis. Median sample size was 126. Colorectal cancers were evaluated in three studies and gastric in two, while breast, melanoma, pancreas, ovary, head and neck and cervix cancers were assessed in one study respectively. The median percentage of cases with HER3 expression was 43%. HER3 expression was associated with worse OS at both 3 and 5 years (OR: 2.23; 95% confidence interval [CI], 1.74 to 2.86, p < 0.001 and OR: 2.25; 95% CI, 1.77 to 2.86, p < 0.001, respectively). Among studies with known HER2 over-expression (breast, gastric and ovary cancers), the magnitude of effect of HER3 on OS was significantly greater (3-years OS OR: 3.33, 95% CI, 2.30 to 4.83, p < 0.001 and 5-year OS OR: 3.17, 95% CI, 2.23 to 4.49, p < 0.001).

Conclusion

Expression of HER3 is associated with worse survival in solid tumors. The effect of HER3 may be greater in those tumors where HER2 is also over-expressed. A validated method for HER3 assessment is required, but the potential clinical benefit from targeting HER3 appears favorable.

Disclosure

All authors have declared no conflicts of interest.