How the Decipher Genomic Test Helps Guide Prostate Cancer Treatment Decisions

Table of Contents

• Key Points
• Background: Why Prostate Cancer Risk Assessment Needs Improvement
• What Is the Decipher Genomic Classifier?
• Low-Risk Prostate Cancer: Identifying Safe Candidates for Surveillance
• Intermediate-Risk Prostate Cancer: Refining Treatment Selection
• High-Risk Prostate Cancer: Guiding Treatment Intensification
• After Radical Prostatectomy: Guiding Salvage Treatment
• Ongoing Clinical Trials
• Challenges and Limitations
• Conclusion
• What This Means for Patients
• Frequently Asked Questions
• Source Information

Key Points

• The Decipher genomic classifier is a 22-gene test that estimates the risk of metastasis, biochemical recurrence, and prostate cancer-specific mortality from prostate cancer tissue.
• In a prospective study, low-score patients (below 0.45) remained on active surveillance more than twice as long as high-score patients, with a median delay of 19.4 months.
• In a meta-analysis of three trials, high-score patients had a 10-year distant metastasis rate of 26% versus 6% for low-score patients.
• The test is prognostic, not predictive: it estimates risk but does not directly predict how a patient will respond to a specific treatment.
• Two ongoing Phase III trials, NRG GU-009 and NRG GU-010, are evaluating the test's use in guiding treatment intensification or de-intensification.

Background: Why Prostate Cancer Risk Assessment Needs Improvement

Prostate cancer is the second most common cancer in men worldwide. In 2022, doctors diagnosed an estimated 1.5 million new cases and recorded nearly 400,000 deaths from the disease globally.

The behavior of prostate cancer varies widely between patients. Some cancers grow so slowly that they can be managed with careful monitoring alone. Other cancers grow aggressively and require surgery, radiation, hormone therapy, or a combination of treatments.

Doctors traditionally assess prostate cancer risk using several factors:

• Prostate-specific antigen (PSA) levels — a protein in the blood that can be elevated when prostate cancer is present
• Gleason score — a measure of how abnormal the cancer cells look under a microscope
• Tumor stage — how far the cancer has spread within or beyond the prostate
• Percentage of positive biopsy cores — how many tissue samples contain cancer

The National Comprehensive Cancer Network (NCCN) uses these factors to classify patients into low-risk, intermediate-risk, and high-risk groups. This classification guides treatment decisions, including active surveillance, radical prostatectomy (surgical removal of the prostate), radiation therapy, and androgen deprivation therapy (ADT, which lowers male hormones that fuel cancer growth).

However, these traditional clinical and pathological factors do not fully capture the biological diversity of prostate cancer. This limitation leads to two problems: some patients receive treatment they do not need (overtreatment), while others receive too little treatment for aggressive disease (undertreatment).

Advances in molecular oncology have allowed researchers to develop genomic tests that provide additional information beyond traditional factors. These tests include Ki-67 immunohistochemistry, the cell cycle progression score (Prolaris), the genomic prostate score (Oncotype DX), and the 22-gene genomic classifier (Decipher). Among these, the Decipher genomic classifier has become the most widely used molecular prognostic test in clinical practice.

What Is the Decipher Genomic Classifier?

The Decipher genomic classifier is a test that analyzes the activity of 22 specific genes in prostate cancer tissue. The test uses whole transcriptome RNA expression profiling, which measures how actively these genes are producing their products.

By analyzing these 22 genes, the test estimates the risk of three important outcomes:

• Metastasis — cancer spreading to other parts of the body
• Biochemical recurrence (BCR) — a rise in PSA levels after treatment, which may indicate the cancer has returned
• Prostate cancer-specific mortality (PCSM) — death caused by prostate cancer

The Decipher test was originally developed for patients who had already undergone radical prostatectomy, to predict whether their cancer would progress. Since then, it has shown usefulness in multiple clinical situations, including localized disease, rising PSA after surgery, and high-risk prostate cancer that may require stronger treatment.

This review article examines how the 22-gene genomic classifier affects treatment decisions for patients with low-risk, intermediate-risk, and high-risk prostate cancer. The review article also examines the genomic classifier's role in managing patients after radical prostatectomy.

Low-Risk Prostate Cancer: Identifying Safe Candidates for Surveillance

For patients with low-risk prostate cancer, the main challenge is determining who can safely remain on active surveillance and who may need early treatment. Active surveillance involves regular monitoring with PSA tests, biopsies, and imaging rather than immediate treatment.

Traditional risk assessment based on PSA levels, Gleason score, and clinical staging often lacks the precision to fully capture disease biology. The Decipher genomic classifier provides additional molecular information that improves risk stratification.

Prospective evidence from the Michigan Urological Surgery Improvement Collaborative showed important results. Patients with low genomic classifier scores (below 0.45) remained on active surveillance for more than twice as long as those with high-risk scores. The median delay before requiring treatment was 19.4 months for patients with low scores.

Additional data from a study by Kim and colleagues showed that patients with the lowest genomic classifier scores had a very high negative predictive value. That negative predictive value was for adverse pathology at the time of radical prostatectomy. For scores of 0.2 or lower, this negative predictive value reached 96%.

This means that patients with low genomic risk have a minimal likelihood of having aggressive disease. This finding reinforces the safety of active surveillance for this group of patients.

Intermediate-Risk Prostate Cancer: Refining Treatment Selection

For patients with intermediate-risk prostate cancer, treatment decisions involve balancing the risk of disease progression against the side effects of stronger therapy. The Decipher genomic classifier provides molecular information that helps doctors distinguish patients who can be safely treated with radiation therapy alone. The Decipher genomic classifier also helps doctors identify those who would benefit from adding short-term androgen deprivation therapy.

Data from the NRG/RTOG 0126 Phase III randomized trial provided important evidence. Patients with a low genomic classifier score (0.45 or below) had favorable long-term outcomes with radiation therapy alone. Their 10-year distant metastasis rate was only 4%.

In contrast, patients with a high genomic classifier score (0.60 or above) had a 16% distant metastasis rate. This finding suggests that treatment intensification with short-term androgen deprivation therapy may provide significant benefits in reducing metastasis risk for these patients.

These results highlight the growing role of molecular classifiers in tailoring therapy for intermediate-risk prostate cancer. The genomic classifier helps ensure a more individualized and evidence-based approach to treatment planning.

High-Risk Prostate Cancer: Guiding Treatment Intensification

For patients with high-risk prostate cancer, the Decipher genomic classifier provides critical prognostic information that helps refine treatment intensification strategies.

A meta-analysis combined data from three Phase III randomized trials: NRG/RTOG 92-02, 94-13, and 99-02. The analysis showed that the genomic classifier independently predicted key cancer outcomes, including distant metastasis, biochemical recurrence, and prostate cancer-specific mortality.

The results were striking:

• Patients with high genomic classifier scores had a 10-year distant metastasis rate of 26%
• Patients with low genomic classifier scores had a 10-year distant metastasis rate of only 6%

The benefit of long-term androgen deprivation therapy (24 months) compared with short-term androgen deprivation therapy (4 months) was greatest in patients with high genomic classifier scores. For these high-risk patients, long-term androgen deprivation therapy reduced the distant metastasis risk from 31% to 20%. Patients with low genomic classifier scores derived minimal additional benefit from long-term androgen deprivation therapy.

These findings suggest that the genomic classifier can identify which patients would benefit most from intensified systemic therapy. This information guides more personalized treatment decisions.

After Radical Prostatectomy: Guiding Salvage Treatment

For patients who have undergone radical prostatectomy and have rising PSA levels, the Decipher genomic classifier provides important prognostic information. This information helps guide decisions about salvage radiation therapy and whether to add androgen deprivation therapy.

Data from two Phase III trials (RTOG 96-01 and SAKK 09/10) demonstrated important findings. Patients with high genomic classifier scores (above 0.60) had a significantly higher risk of biochemical progression, clinical progression, and distant metastasis. These high-risk patients showed greater benefit from adding androgen deprivation therapy to salvage radiation therapy.

In the RTOG 96-01 trial, patients with high genomic classifier scores who received androgen deprivation therapy had a 12-year reduction in distant metastasis of 11.2%. Those patients also had a reduction in prostate cancer-specific mortality of 8.4%. In contrast, patients with low genomic classifier scores derived minimal or even negative survival benefit from androgen deprivation therapy.

Similarly, the SAKK 09/10 trial found that patients with high genomic classifier scores had higher rates of salvage androgen deprivation therapy use after radiation therapy compared with low-risk patients.

These findings suggest that using the genomic classifier could individualize treatment decisions. The test helps determine which patients should receive androgen deprivation therapy alongside salvage radiation therapy. The test also helps identify patients who would benefit most from early intervention.

However, an important question remains unanswered. The optimal duration of androgen deprivation therapy (for example, 6 months versus 24 months) based on Decipher genomic classifier risk stratification is still unknown.

Ongoing Clinical Trials

Two large prospective clinical trials are currently underway to provide stronger evidence for the Decipher genomic classifier's role in treatment decision-making.

NRG GU-009 (PREDICT-RT) is an ongoing Phase III study designed to personalize treatment strategies for high-risk prostate cancer based on the Decipher genomic classifier. The trial uses the genomic classifier as an integral biomarker for randomization:

• Patients with lower genomic classifier scores are randomized to radiation therapy with either 12 or 24 months of androgen deprivation therapy. This comparison evaluates whether shorter-duration androgen deprivation therapy can maintain effectiveness while reducing side effects.
• Patients with higher genomic classifier risk or positive lymph nodes are randomized to radiation therapy with 24 months of androgen deprivation therapy alone. Other patients are randomized to intensified treatment with radiation therapy plus 24 months of androgen deprivation therapy plus 24 months of apalutamide. Apalutamide is an androgen receptor pathway inhibitor. This comparison assesses whether adding systemic therapy improves outcomes in this higher-risk population.

By using the genomic classifier as an integral biomarker for trial randomization, NRG GU-009 aims to optimize risk-adapted treatment approaches. The trial seeks to balance treatment intensity with toxicity management in high-risk prostate cancer.

NRG GU-010 (GUIDANCE) is an ongoing Phase III study using Decipher genomic classifier scores to guide treatment de-intensification or intensification for unfavorable intermediate-risk prostate cancer:

• Patients with lower genomic classifier risk are randomized to radiation therapy alone or radiation therapy with short-term (6 months) androgen deprivation therapy. This comparison assesses whether androgen deprivation therapy can be safely omitted.
• Patients with higher genomic classifier risk are randomized to radiation therapy with androgen deprivation therapy or radiation therapy with androgen deprivation therapy plus darolutamide (an androgen receptor pathway antagonist). This comparison evaluates the benefits of intensified systemic therapy.

This trial aims to refine risk-adapted treatment strategies. The goal is to minimize unnecessary toxicity while ensuring that high-risk patients receive adequate therapy. The trial further reinforces the role of the genomic classifier in precision oncology.

Challenges and Limitations

While the 22-gene genomic classifier has shown significant promise in refining risk stratification and guiding treatment decisions, several challenges and limitations remain.

Heterogeneity in study designs is a major concern. Much of the supporting evidence comes from retrospective analyses, which look back at past patient data rather than following patients forward in time. These studies have demonstrated the genomic classifier's prognostic value across various clinical settings. However, the lack of prospective, randomized validation in some treatment scenarios limits how broadly the findings can be applied.

Differences in patient populations, treatment protocols, and follow-up durations across studies contribute to variability in reported outcomes. These differences make it difficult to establish uniform clinical guidelines based on genomic classifier results alone.

Biopsy sample heterogeneity is another limitation. Prostate tumors can be multifocal (having multiple separate areas of cancer), and biopsy sampling can vary. These factors may affect genomic classifier scoring and interpretation.

The integration of novel imaging methods, such as PSMA PET (a type of scan that detects prostate cancer cells), may help refine risk stratification. PSMA PET improves tumor characterization and can guide targeted biopsy approaches.

The genomic classifier is primarily a prognostic test, not a predictive test. This is a key distinction. The test provides valuable risk stratification by estimating the likelihood of metastasis, biochemical recurrence, or prostate cancer-specific mortality. However, it does not directly predict how a patient will respond to a specific treatment.

Despite these challenges, the ongoing large, randomized prospective trials (NRG GU-009 and NRG GU-010) aim to address these limitations. These trials evaluate the clinical utility of the genomic classifier in real-time treatment decision-making. They will provide high-level evidence on how genomic risk stratification can guide treatment de-intensification or intensification. Ultimately, these trials will help bridge the gap between prognostic insights and actionable predictive biomarkers.

Conclusion

The integration of the Decipher genomic classifier into prostate cancer management represents a significant advancement in personalized risk stratification and treatment decision-making.

By providing independent prognostic information beyond traditional clinical factors, the genomic classifier enhances the ability to distinguish which patients may benefit from treatment escalation. The genomic classifier also enhances the ability to distinguish which patients may be safely managed with less intensive approaches.

The results of ongoing prospective clinical trials, such as NRG GU-009 and NRG GU-010, are expected to further solidify the clinical utility of the genomic classifier in real-time treatment selection.

Moving forward, the continued evolution of molecular diagnostics, combined with emerging therapeutic advancements, will further enhance precision oncology in prostate cancer. These developments will help ensure that patients receive the most appropriate, individualized care.

What This Means for Patients

If you or a loved one has been diagnosed with prostate cancer, the Decipher genomic classifier may be a valuable tool in your treatment planning. Here are key points to discuss with your healthcare team:

1. Ask whether genomic testing is appropriate for your situation. The Decipher test can provide additional information beyond PSA levels, Gleason score, and tumor stage.
2. Understand what the test measures. The Decipher genomic classifier estimates the risk of cancer spreading, PSA rising after treatment, and death from prostate cancer. It does not predict how you will respond to specific treatments.
3. Discuss how test results might change your treatment plan. For low-risk patients, a low genomic classifier score may support choosing active surveillance. For intermediate-risk and high-risk patients, the score may help determine whether adding hormone therapy to radiation therapy is beneficial.
4. Recognize the limitations. Most evidence for the Decipher test comes from retrospective studies. Two large prospective trials (NRG GU-009 and NRG GU-010) are ongoing and will provide stronger evidence.
5. Consider clinical trial participation. If you have high-risk or unfavorable intermediate-risk prostate cancer, ask your doctor whether you might be eligible for one of the ongoing clinical trials evaluating genomic classifier-guided treatment.

The field of prostate cancer treatment is rapidly evolving. Genomic tests like the Decipher classifier represent an important step toward personalized medicine, where treatment decisions are tailored to the specific biology of each patient's cancer.

Frequently Asked Questions

What is the Decipher genomic classifier?

The Decipher genomic classifier is a test that analyzes the activity of 22 specific genes in prostate cancer tissue using whole transcriptome RNA expression profiling. It estimates the risk of three outcomes: metastasis (cancer spreading), biochemical recurrence (a rise in PSA after treatment), and prostate cancer-specific mortality (death from prostate cancer). It was originally developed for patients who had already undergone radical prostatectomy.

Who might benefit from the Decipher test?

The test may be useful for patients with low-risk, intermediate-risk, or high-risk prostate cancer, and for those who have had surgery and have rising PSA levels. It provides additional molecular information beyond PSA, Gleason score, and tumor stage. Ask your healthcare team whether genomic testing is appropriate for your situation.

How might a low Decipher score affect my treatment?

In a prospective study, patients with low genomic classifier scores (below 0.45) remained on active surveillance more than twice as long as those with high scores, with a median delay before treatment of 19.4 months. Another study found that scores of 0.2 or lower had a 96% negative predictive value for adverse pathology at surgery, suggesting a low likelihood of aggressive disease.

What does a high Decipher score mean for my treatment?

A high score indicates a higher risk of metastasis, biochemical recurrence, and prostate cancer-specific mortality. In a meta-analysis of three trials, high-score patients had a 10-year distant metastasis rate of 26% versus 6% for low-score patients. High-score patients benefited more from long-term androgen deprivation therapy, which reduced distant metastasis risk from 31% to 20%.

Does the Decipher test predict how I will respond to treatment?

No. The Decipher genomic classifier is primarily a prognostic test, not a predictive test. It estimates the likelihood of metastasis, biochemical recurrence, or prostate cancer-specific mortality, but it does not directly predict how a patient will respond to a specific treatment. Discuss with your doctor how the results might inform your treatment plan.

What are the limitations of the Decipher test?

Most supporting evidence comes from retrospective studies, which look back at past patient data. There is a lack of prospective, randomized validation in some treatment scenarios. Differences in patient populations, treatment protocols, and follow-up durations across studies contribute to variability. Biopsy sample heterogeneity and multifocal tumors may also affect scoring and interpretation.

Are there ongoing trials for the Decipher test?

Yes. Two large prospective Phase III trials are underway. NRG GU-009 (PREDICT-RT) uses the genomic classifier to personalize treatment for high-risk prostate cancer. NRG GU-010 (GUIDANCE) uses it to guide treatment de-intensification or intensification for unfavorable intermediate-risk prostate cancer. These trials aim to provide stronger evidence for the test's role in treatment decision-making.

When should a patient with prostate cancer seek a second opinion about whether the Decipher genomic test should guide their treatment?

A second opinion can help when the treatment choice hinges on genomic risk. For low-risk disease, a score below 0.45 may support staying on active surveillance, where the median delay before treatment was 19.4 months. For intermediate-risk disease, a score of 0.45 or below was linked to a 10-year distant metastasis rate of 4%, versus 16% for scores of 0.60 or above. For high-risk disease, long-term androgen deprivation reduced distant metastasis from 31% to 20% in high-score patients. Diagnostic Detectives Network provides independent expert second opinions.

Source Information

Original Article Title: The Clinical Impact of the Decipher Genomic Classifier in Prostate Cancer.

Journal: The Eurasian journal of medicine

DOI: 10.5152/eurasianjmed.2025.25828

License: CC BY (open access)

Authors: Li S, A Berg S, Sayan M.

Author Affiliations: Department of Radiation Oncology, Brigham and Women's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Lank Center for Genitourinary Oncology at Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA

Publication: Eurasian Journal of Medicine, 2025; Volume 57, Issue 2, Pages 1-4

DOI: 10.5152/eurasianjmed.2025.25828

Article Type: Review Article

Received: February 28, 2025 | Accepted: March 6, 2025 | Publication Date: May 5, 2025

Peer Review: Externally peer-reviewed

Funding: The authors declared that this study received no financial support.

Conflicts of Interest: The authors declared no conflicts of interest.

This patient-friendly article is based on peer-reviewed research. It is intended for educational purposes and should not replace consultation with a qualified healthcare provider. Patients should discuss their individual medical situation with their healthcare team.