Prognostic potential of epithelial to mesenchymal transition in prostate cancer at first presentation
A. Al-Sukaini, C. Hart, R. Robinson, M. Brown, N. Clarke , Cancer Research , DOI: 10.1038/nature14426
Introduction and Objective: Metastatic progression of prostate cancer requires a change of state, epithelial to mesenchymal transition (EMT), reducing cell to cell adherence and contact, with associated cell motility and invasion. EMT is one of the hallmarks of cancer and characterisation of the EMT process has defined a panel of EMT biomarkers. Here we investigate the potential of an EMT panel of biomarkers in an unscreened population at first presentation with prostate cancer.
Methods: A prostate Tissue Micro Array (TMA) comprising 2,450 cores containing normal adjacent, prostatic intraepithelial neoplasia and malignant prostate tissue from 524 diagnostic biopsies, linked to an extensive clinical database with long-term outcome, was studied. Expression of a panel of EMT biomarkers, including E-cadherin and vimentin, was assessed using an automated, high throughput fluorescent staining (Leica BOND-MAX), image capture (Carl Zeiss Microimaging Mirax scanner) and quantitative image analysis (Definiens Tissue Studio) protocol. Definiens H-Score was converted to pathological scores prior to univariate and multivariate Cox proportional hazards regression analysis in SPSS.
Results: Expression of an EMT profile predicted a significant reduction in both overall and cancer specific survival. In univariate analysis, low or negative E-cadherin staining was associated with a reduction in median overall survival by 45 months (95% CI: 10.4-79.6; P<0.0001) and a cancer specific mean survival of 80.1 months (95% CI: 45.7-114.5; P<0.0001) when compared to high and intermediate E-cadherin staining. Similarly, high EMT expression, defined as loss of E-cadherin and presence of vimentin, was compared to low EMT expression, defined as preserved E-cadherin and the absence of vimentin. There was a greater reduction in overall median survival in high EMT tumours of 54 months (95% CI: 12.5-95.5; p<0.0001) and cancer specific survival of 93.2 months (95% CI: 62.8-123.7; p<0.0001) when compared to low EMT tumours. Stage, grade, PSA at diagnosis and EMT status was included in the multivariate analysis for cancer specific survival. Both Gleason grade (p = 0.017) and EMT status (p = 0.030) were found to be significant prognostic factors in predicting cancer specific survival.
Conclusions: Loss of E-cadherin and concomitant expression of the EMT marker vimentin are powerful predictors of prostate cancer outcome at first presentation.