Real-world data show clinical utility of novel genomic test in early-stage prostate cancer

DecipherProstate Biopsy, a 22-gene microarray-based genomic classifier, showed potential as a tool to help guide decisions between active surveillance and radical treatment in men with early-stage prostate cancer, according to a real-world study published in Prostate Cancer and Prostatic Diseases.^1,2

"We have long needed better risk stratification tools for early-stage prostate cancer patients to reduce the uncertainty that is often part of initial treatment decisions," Randy Vince Jr., MD, Society of Urologic Oncology Fellow, University of Michigan, and the paper's lead author, stated in a press release. "The findings from our analysis, which show that men with high Decipher scores are more likely to transition off of active surveillance and are over 2-fold times more likely to experience treatment failure after initial therapy, provide evidence that molecular testing could have significant utility in this setting."

The data for the study were obtained from the Michigan Urological Surgery Improvement Collaborative (MUSIC) registry. The study included 855 men with localized prostate cancer who received Decipher testing between February 2015 and October 2019.

The median patient age was 66 (interquartile range [IQR], 60-72), including 500 patients aged 65 to 74. Regarding race, 75% of patients were White, 13.1% were Black, 0.9% were Asian, 0.1% were Native American, and 10.9% of patients were unknown/other. The median body mass index (BMI) was 28.6 kg/m2. Specifically, 19.1% of patients had a BMI ≤25 kg/m2, 46% of patients had a BMI between 25.1 kg/m2 and 30 kg/m2 and 34.9% of patients had a BMI >30 kg/m2. The median PSA at baseline was 6.1 ng/ml. The majority (59.1%) of patients had a PSA between 4.1 ng/ml and 10 ng/ml.

About one-third (32.6%) of patients had 1 to 2 positive cores, 26.4% had 3 to 4 positive cores, and 41% had >4 positive cores. Regarding NCCN risk group status, 19.1% were low, 30.9% were favorable/intermediate, 39.7% were unfavorable/intermediate, and 10.3% were high.

Across the study population, 31% (n = 264) of patients elected active surveillance upfront and 53% (n = 454) chose to receive radical therapy. The investigators adjusted for several factors—risk status, PSA, age, BMI, prostate volume, positive cores—and found that in men who chose active surveillance, there was an independent association between a high-risk Decipher score and a shorter time to conversion from active surveillance to radical therapy (HR, 2.51; P <.001). The median time on active surveillance was 13.6 months in men with high-risk Decipher scores versus 33 months in patients with low/intermediate scores (P <.001).

A similar pattern was observed in patients receiving definitive treatment. Among 479 evaluable patients who underwent radical therapy either upfront or following active surveillance, there was an independent association between a high-risk Decipher score and a significantly shorter time to treatment failure (P = .007).

“We believe this real-world study and the resulting findings fill a critical gap in prostate cancer treatment, which is the need for an objective tool that can help physicians identify those early-stage patients who are good candidates for active surveillance as well as those who should move directly to definitive treatment with surgery or radiotherapy,” Elai Davicioni, PhD, senior vice president, Scientific and Clinical Operations, Urologic Cancers, at Veracyte, the developer of the Decipher test, stated in the press release.

Reference

1. New Study Suggests Decipher Prostate Biopsy Test May Help Guide Use of Active Surveillance in Prostate Cancer. Published online July 27, 2021. Accessed July 30, 2021. https://bwnews.pr/3C8FYeb.

2. Vince RA Jr, Jiang R, Qi J, et al. Impact of Decipher Biopsy testing on clinical outcomes in localized prostate cancer in a prospective statewide collaborative [published online ahead of print June 20, 2021]. Prostate Cancer Prostatic Dis. doi: 10.1038/s41391-021-00428-y