BACKGROUND: This study examines the combined effect of two common genetic alterations, ERG and PTEN, in prostate carcinoma progression.
METHODS: Prostate tissue from 90 patients having unilateral capsular penetrating lesions, and a contra-lateral organ confined second lesion, were examined by immunohistochemistry for the expression of the TMPRSS2:ERG transformation product ERG and the loss of expression of PTEN, a powerful phosphatase inhibiting the PI3 kinase pathway. Multivariate logistic regression was carried out to analyze the data.
RESULTS: After adjusting for Gleason score, the odds of having capsular penetration were 5.19 times higher (P = 0.015) for ERG+/PTEN- group as compared to the wild type (ERG-/PTEN+).
CONCLUSIONS: This study presents the first evidence that ERG over expression and PTEN deletion is associated with greater risk of capsular penetration. Although further studies are needed, these results have the potential to change clinical assessment for prostate cancer.