['To determine whether PTEN status in prostate biopsy represents a predictor of intermediate and long-term oncological outcomes after radical prostatectomy, and whether PTEN status predicts response to androgen deprivation therapy.', 'In a retrospective analysis of 77 men treated by radical prostatectomy who underwent diagnostic biopsy between 1992-2006, biopsy samples were stained for PTEN expression by the PREZEON assay with >10% staining reported as positive. Cox proportional hazards and log-rank models were used to assess the correlation between PTEN loss and clinical outcomes.', 'During a median follow-up period after radical prostatectomy of 8.8 years, 39 men (51%) developed biochemical recurrence, four (5%) had castration-resistant prostate cancer, two (3%) had metastasis and two (3%) died from prostate cancer. PTEN loss was not significantly associated with biochemical recurrence (hazard ratio 2.1, 95% confidence interval 0.9-5.1, P = 0.10), but significantly predicted increased risk of castration-resistant prostate cancer, metastasis and prostate cancer-specific mortality (all log-rank, P < 0.0001), and time from androgen deprivation therapy to castration-resistant prostate cancer (log-rank, P = 0.003). No patient without PTEN loss developed metastases or died from prostate cancer.'] Does pTEN loss in biopsy tissue predict poor clinical outcomes in prostate cancer?