What we know now: PTEN loss is a consistent marker of aggressive disease
Across multiple studies, PTEN loss is strongly associated with more aggressive prostate cancer and worse outcomes. In a 2025 study of high-risk localized patients, those with PTEN loss were more likely to present with advanced-stage disease (33% vs. 19%) and had higher mortality (32% vs. 22%) [1]. Similarly, in a 2021 study of men with newly diagnosed metastatic prostate cancer, PTEN loss independently predicted shorter progression-free and overall survival, with a 67% increased risk of progression and a 95% increased risk of death [7]. These findings converge across different disease stages, from localized to metastatic, reinforcing PTEN's role as a prognostic marker.
The prognostic value extends to intermediate-risk patients, where treatment decisions are often hardest. A 2025 study of patients diagnosed via MRI-targeted biopsy found that PTEN loss was an independent predictor of biochemical recurrence after surgery, with a hazard ratio of 8.5—meaning these patients were 8.5 times more likely to experience recurrence [3]. This is particularly useful because intermediate-risk prostate cancer is a gray zone where doctors struggle to predict who needs aggressive treatment.
The catch: PTEN testing is not standardized enough for routine use
The biggest barrier to using PTEN status in clinical practice is the lack of reliable, standardized testing. A 2024 German ring trial, which sent the same 90 prostate cancer samples to ten university pathology institutes, found that PTEN loss rates varied dramatically—from 12.5% to 51.2%—depending on the lab [4]. This means a patient could be told they have PTEN loss at one hospital and intact PTEN at another, making it unreliable for treatment decisions. The study did find that all cases with confirmed genetic deletions were unanimously identified, but the test was not specific—many samples without deletions were also called 'loss'.
Efforts are underway to improve consistency. Machine learning (ML) has shown promise: a 2021 study developed an automated PTEN scoring system that matched human experts with high accuracy (area under the curve 0.987) [6]. However, this is still in development and not yet widely available. Until testing is standardized and validated across labs, PTEN status cannot be a practical biomarker for routine clinical use.
Does PTEN status actually change treatment? The evidence is mixed
The ultimate question is whether knowing PTEN status helps doctors choose a better treatment. So far, the evidence is promising but not conclusive. A 2025 study suggested that high-risk patients with PTEN loss might benefit more from radiation therapy (RT) than surgery, but this was a retrospective analysis and not a randomized trial [1]. In metastatic castration-resistant prostate cancer (mCRPC), a 2024 real-world study found that PTEN loss was associated with worse survival regardless of whether patients received hormone therapy or chemotherapy, suggesting it doesn't help choose between those options [2].
However, PTEN loss may identify patients who could benefit from targeted therapies. A phase I/II trial combining a PI3K inhibitor (GSK2636771) with pembrolizumab in mCRPC patients with PTEN loss showed durable responses in a heavily pretreated population—two patients had partial responses lasting over a year [5]. This suggests that PTEN loss could be a predictive biomarker for specific drug combinations, but larger trials are needed. Additionally, a 2026 preclinical study found that PTEN loss increased sensitivity to AKT inhibitors, supporting the idea of targeted therapy [8]. Yet, these are early-stage findings, and no treatment guideline currently recommends using PTEN status to select therapy.
About These Sources
This answer is built on 8 peer-reviewed studies — published from 2021 to 2026, 5 from 2024 or later, 4 in Q1 journals — selected as the most relevant from 13 studies that passed quality screening, drawn from 71 papers retrieved from a database of over 500 million.
Sources used in this answer
Assessing the impact of PTEN loss on outcomes in high-/very high-risk, advanced hormone-sensitive prostate cancer patients: Institutional retrospective study.
In a retrospective cohort of 311 high-risk prostate cancer patients, PTEN loss was associated with more advanced stage (33% vs. 19% stage IV) and higher mortality (32% vs. 22%), but no significant overall survival difference; suggested RT-based treatment may be better for PTEN-loss patients.
Real-World Overall Survival and Treatment Patterns by <i>PTEN</i> Status in Metastatic Castration-Resistant Prostate Cancer
In a real-world cohort of mCRPC patients, PTEN loss of function was associated with decreased survival (HR 1.61, p=0.024) regardless of first-line treatment type, and PTEN-loss patients were less likely to receive second-line therapy.
The prognostic value of PTEN expression in localized prostate cancer
In 213 patients diagnosed via MRI-targeted biopsy, PTEN loss was an independent predictor of biochemical recurrence after radical prostatectomy (HR 8.5, p=0.03), especially in intermediate-risk patients.
High interobserver variability of PTEN immunohistochemistry defining PTEN status in low- to intermediate-risk prostate cancer: results of the first German ring trial
In a German ring trial with 90 prostate cancer cases across 10 labs, PTEN IHC interpretation varied widely (12.5–51.2% loss rates), but all cases with hemizygous deletions were unanimously identified; pAKT IHC was suggested for equivocal cases.
Phase I/II study of the selective PI3Kβ inhibitor GSK2636771 in combination with pembrolizumab in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) and PTEN loss.
In a phase I/II trial of GSK2636771 (PI3Kβ inhibitor) plus pembrolizumab in 12 mCRPC patients with PTEN loss, 2 partial responses lasting >12 months were observed, with acceptable safety but notable rash and dose reductions.
PTEN and DNA Ploidy Status by Machine Learning in Prostate Cancer
A machine learning model for PTEN IHC scoring achieved high concordance with human experts (AUC 0.987) and, combined with DNA ploidy, predicted biochemical recurrence (HR 4.63 for both markers) in validation cohorts.
Prognostic value of PTEN in de novo diagnosed metastatic prostate cancer
In 205 patients with de novo metastatic castration-naïve prostate cancer, PTEN loss (28.3%) independently predicted shorter progression-free survival (HR 1.67) and overall survival (HR 1.95), even in low-volume disease.
Abstract A043: Functional PTEN loss rewires AR-AKT crosstalk and alters therapeutic response in a novel AR-positive prostate cancer model
In a novel AR-positive PTEN knockout prostate cancer model, PTEN loss increased sensitivity to AKT inhibitor (IC50 reduced from 0.66 μM to 0.18–0.50 μM) and altered AR inhibitor response, supporting dual-pathway targeting.