Gene classifier (GC) tests for prostate cancer (PCa) may influence treatment decisions despite lack of evidence for long-term outcomes. A systematic review of genomic classifier tests confirms they may influence treatment decisions for patients with localized prostate cancer, but without giving optimal results.
There is a need for better data on their cost-effectiveness, clinical utility, and their impact on racial and ethnic groups, particularly Black men. Notably, this pattern of utility differed across GC test types, however, with Genomic Prostate Score (GPS)-based studies, few patients were reclassified to a higher risk category.
The study appears in Annals of Internal Medicine. The lead author is Amir Alishahi Tabriz, MD, PhD, department of health outcomes and behavior, Moffitt Cancer Center. The team was comprised of researchers from the Durham VA Health Care System and collaborators.
In an accompanying editorial, the authors wrote, “Personalized treatment of localized prostate cancer (PCa) remains a critical unmet need. Decisions about active surveillance (AS), radical prostatectomy, or definitive radiation—with or without androgen deprivation therapy (ADT)—are guided by initial risk stratification into low-, intermediate-, or high-risk groups. This stratification relies on clinical staging determined by prostate magnetic resonance imaging, biopsy pathology, and prostate-specific antigen levels. Although simple and actionable, its predictive value for treatment outcomes is suboptimal.
Prostate cancer is the most common cancer among men, with cases ranging from barely noticeable to highly aggressive ones requiring serious treatment. Determining who needs which type of treatment remains a significant challenge. Traditionally, cinicians rely on tools like the NCCN guidelines, which assess tumor stage, PSA levels, and Gleason grades. However, these tools are not perfect and can sometimes lead to undertreatment.
Tests like Decipher by Veracyte, Prolaris by Myriad Genetics, and Oncotyp DX Genomic Prostate Score (GPS) by MDx offer a genetic snapshot of tumor aggressiveness, potentially catching things that clinical tools might miss. Despite the potential of these tests, their use in clinical practice is inconsistent due to conflicting guidelines.
This team reviewed 19 studies to assess the impact of these tissue-based genomic tests on risk stratification and treatment decisions for localized prostate cancer. The researchers analyzed test type, quality, population characteristics, risk reclassification and recommended and/or received treatment intensity.
They found that in observational studies with low risk of bias, most patients with low or very low baseline risk did not see an increase in risk classification after GC testing. This pattern differed across GC test types. However, with GPS-based studies they found 0–11.9% of patients were reclassified to a higher risk category, versus Decipher-based studies finding 12.8% to 17.1% reclassified to a higher risk category.
In a randomized trial, reclassification to higher risk was more prevalent than in the observational studies examined. Observational studies indicated that GC testing often led to more patients opting for conservative management options like active surveillance.
The researchers noted that the differences in results from observational and randomized trials emphasize the need for well-designed trials evaluating the impact of GC tests in management of PCa to inform patient-clinician decision-making.
