1587P - Low RBM3 protein expression correlates with clinical stage, prognostic index and increased risk of treatment failure in testicular non-seminomatous...

Date 28 September 2014
Event ESMO 2014
Session Poster Display session
Topics Germ Cell Tumours
Translational Research
Presenter Sven-Erik Olofsson
Citation Annals of Oncology (2014) 25 (suppl_4): iv546-iv563. 10.1093/annonc/mdu358
Authors S. Olofsson1, B. Nodin2, A. Gaber2, J. Eberhard2, M. Uhlén3, E. Cavallin-Ståhl2, K. Jirström2
  • 1Department Of Clinical Sciences, Division Of Oncology And Pathology, Lund University, Skåne University Hospital, 22185 - Lund/SE
  • 2Department Of Clinical Sciences, Division Of Oncology And Pathology, Lund University, Skåne University Hospital, Lund/SE
  • 3Science For Life Laboratory And School Of Biotechnology, AlbaNova University Center, Royal Institute of Technology, Stockholm, Sweden, Stockholm/SE

Abstract

Aim

Expression of the RNA-binding motif protein 3 (RBM3) has in previous studies been shown to correlate with favourable clinicopathological parameters and prognosis in a number of cancer forms. The aim of this study was to examine the expression and prognostic ability of RBM3 in patients with non-seminomatous germ cell tumours (NSGCT).

Methods

Immunohistochemical RBM3 expression was analysed in tissue microarrays with tumours from 206 patients with NSGCT. Chi-square test was applied to analyze associations between RBM3 expression and clinicopathological parameters. Kaplan-Meier analysis was used to assess the impact of RBM3 expression on cancer-specific survival (CSS) and progression-free survival (PFS). Cox regression proportional hazards models were used to estimate the relative risk for progression in both uni- and multivariable analysis.

Results

In the entire cohort, there was a significant association between clinical stage (p=0.044) and RBM3 expression. Low RBM3 expression correlated with a significantly reduced PFS [67.7% versus 87.8% (p=0.001)] and CSS [87.5% versus 97.3% (p=0.047)]. For patients with metastatic disease (n=88), significant associations were found between RBM3 expression and IGCCC prognostic index (p=0.007), combined tumor marker status (p=0.001) and HCG level (p=0.010). The PFS was significantly inferior for patients with low tumour-specific RBM3 expression [40.0% versus 73.0% (p=0.002)], and this association remained significant in a multivariable model (HR=2.98; 95% CI 1.14, 7.75).

Conclusions

Low RBM3 expression is significantly associated with a worse IGCCC-prognostic index and is an independent predictor of disease progression in metastatic NSGCT. These findings suggest that RBM3 may be a potential biomarker for treatment stratification in patients with metastatic non-seminomatous germ cell tumours, and therefore merit further validation.

Disclosure

All authors have declared no conflicts of interest.