Genomic Test Does Not Increase Active Surveillance Acceptance for Treating Favorable-Risk Prostate Cancer

The Genomic Prostate Score (GPS) did not increase active surveillance acceptance compared with conventional risk counseling among patients with favorable-risk prostate cancer, according to data published in the Journal of Clinical Oncology.

More, active surveillance acceptance for managing patients with this disease was high overall regardless of race and for patients who received either the GPS assay or conventional risk counseling.

“In this trial, acceptance of active surveillance for management of relatively favorable-risk prostate cancer was remarkably high, regardless of race, both among men who received the GPS prognostic assay and those who received only conventional risk counseling,” wrote the investigators. “Thus, we found that the GPS assay did not increase active surveillance acceptance, and there was no apparent difference in its effect associated with race.”

The patient population included 200 men from 3 hospitals in Chicago with very low to low-intermediate risk prostate cancer as defined by the National Comprehensive Cancer Network (NCCN). The cohort, which was comprised of 70% Black men, was randomly assigned to standard counseling either with or without the 12-gene GPS assay.

The primary end point was the patient’s treatment choice at the time of second postdiagnosis visit.

Overall, GPS assignment was associated with a slightly lower likelihood of selecting active surveillance compared with immediate therapy (P = .067). When the 10 men assigned to GPS who did not receive a result were removed from the analysis, the team found a slightly stronger association (P = .029).

More, when introducing health literacy into the analysis, the research team found that men with below-median health literacy were significantly less likely to choose active surveillance (odds ratio [OR], 0.16; 95% CI, 0.04-0.63) compared with the control population (1.12; 95% CI, 0.40-3.19). No difference was observed among patients with higher health literacy.

When evaluating the shift in NCCN risk post-GPS testing, 69% of the men who were classified as having low-intermediate risk prostate cancer had GPS scores consistent with those with unfavorable intermediate or high-risk cancer.

“Although the power to detect a significant increase in active surveillance was limited by high baseline acceptance, we observed a marginally significant decrease in active surveillance adoption among the GPS group, largely because of men with low intermediate risk who had GPS results consistent with a higher NCCN risk level,” wrote the investigators. “The GPS effect was highly dependent on health literacy, with essentially no effect among men with higher literacy, but much lower adoption of active surveillance among men with low health literacy.”

Moving forward, the research emphasized the importance of understanding the impact of biomarkers on cancer treatment decisions and the quality of those decisions for diverse patient populations. The team stressed that any valuable strategy to address racial disparities for prostate cancer outcomes should include active surveillance.

Future analyses should explore the psychometric variables of GPS. More, longer follow-ups are ongoing and are necessary to better understand treatment-related morbidity, active surveillance adherence, and adverse reclassification. Studies also focusing on the impact of GPS combined with “pre- or post-biopsy magnetic resonance imaging” should be pursued.

Reference

Murphy AB, Abern MR, Liu L, et al. Impact of a Genomic Test on Treatment Decision in a Predominantly African American Population With Favorable-Risk Prostate Cancer: A Randomized Trial. J Clin Oncol. Published online April 9, 2021. doi:10.1200/JCO.20.02997