914P - The prognostic value of periostin expression in human prostate cancer

Date 29 September 2012
Event ESMO Congress 2012
Session Poster presentation I
Topics Prostate Cancer
Translational Research
Presenter Pier Nuzzo
Authors P.V. Nuzzo1, A. Rubagotti2, L. Zinoli2, F. Ricci1, S. Salvi3, S. Boccardo3, M. Truini3, F. Boccardo4
  • 1Department Of Internal Medicine (dimi), University of Genoa, 16132 - Genoa/IT
  • 2Medical Oncology B, IRCCS AOU San Martino - Ist and University of Genoa, 16132 - Genoa/IT
  • 3Department Of Pathology, IRCCS AOU San Martino-IST, 16132 - Genoa/IT
  • 4Dept. Of Medical Oncology B, IRCCS AOU San Martino - Ist and University of Genoa, 16132 - Genoa/IT

Abstract

Background

Prostate cancer (PCa) has become the most common malignancy among men. Many studies have focused on researching proteins of the extracellular matrix (ECM) for identifying novel tumors markers. Periostin (POSTN), an ECM protein produced by fibroblasts, seems to play a relevant role in human carcinogenesis.

Purpose

To investigate POSTN expression in PCa tissue specimens and in normal peritumoral specimens, in order to conform its role in carcinogenesis and to evaluate its putative prognostic value also as a function of its compartmentalization.

Methods

POSTN expression in PCa cells and peritumoral stroma was immunoistochemically evaluated in a cohort of 90 patients undergoing retropubic prostatectomy by an immuno-reactive score (IRS) based on the intensity of immunocoloration and the quantity of stained cells. The correlation with clinical pathological data and the risk of biochemical relapse and death was investigated on a retrospective basis.

Results

Both stromal and epithelial POSTN expression were significantly increased in tumor tissues as compared to normal tissues (p < 0.000 and p = 0.001). In tumor tissues, stromal expression was significantly higher than epithelial expression (p = 0.003). A significant correlation between POSTN epithelial expression and capsular penetration was found (p = 0.03). At a median follow-up time of 134.4 months (range, 33.7-178.2), 44 patients progressed and 19 died. While a high stromal (IRS value = 12, corresponding to the 75° percentile) POSTN expression was significantly associated with a shorter overall survival (p = 0.008), a low epithelial score (IRS< = 2, also corresponding to the 75° percentile) was significantly correlated with a shorter PSA-free survival (p = 0.04). The patients showing both a high stromal expression (IRS = 12) and a low epithelial expression (IRS≤ 2) constituted a subgroup with shortest PSA-free (p = 0.004) and shortest overall survival (p = 0.002).

Conclusions

Our findings suggest that POSTN might play a relevant role in prostate tumorigenesis. They should be regarded as explorative and should be confirmed in a much larger set, also in order to better understand the different role of POSTN associated with its different compartmentalization. Keywords: Periostin, prostate cancer, extracellular matrix (ECM).

Disclosure

All authors have declared no conflicts of interest.