Study: PCa genomic test reduces decisional conflict

Chicago-For men with high-risk pathology at radical prostatectomy, exposure to results of a genomic test that classifies 5-year risk of metastasis reduces decisional conflict, according to findings of a prospective study presented at the American Society of Clinical Oncology annual meeting in Chicago.  

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The research also demonstrated that information from the genomic test, Decipher, lowers provider uncertainty about treatment recommendations and alters treatment intensity recommendations.

Dr. Gore“There is a lot of uncertainty about proceeding with adjuvant therapy because while randomized controlled trials show that it decreases the risk of biochemical progression, we are still awaiting definitive evidence that it affects clinical metastasis or survival. Previous studies evaluating the impact of prostate cancer biomarker tests on treatment recommendations have looked at decision change. However, our study is novel in that we investigated an effect on decision quality using a validated instrument,” said first author John L. Gore, MD, MS.

“The results indicate that knowledge from the genomic classifier test gives patients with high-risk features and their urologists greater confidence that they are making the right decision about adjuvant treatment,” added Dr. Gore, associate professor of urology, University of Washington, Seattle, and co-principal investigator with Daniel W. Lin, MD, professor and chief of urologic oncology at the University of Washington.

The study included data for 141 men enrolled by 43 urologists practicing in community and academic settings. Eligible patients had extracapsular extension, seminal vesicle invasion, or positive surgical margins found at radical prostatectomy. According to the genomic classifier results, about half of the men had a low risk of disease progression within 5 years, 20% were classified as being intermediate risk, and the rest were at high risk.

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The study collected data about provider treatment recommendations before and after the urologists knew the genomic classifier results. In addition, both providers and patients completed a validated questionnaire for assessing decisional conflict (Decisional Conflict Scale) on patient enrollment and after seeing the genomic classifier results.

Next: Conflict scores drop for patients, urologists

Conflict scores drop for patients, urologists

Following exposure to the genomic classifier results, the median DCS score decreased (indicating higher decision quality) for both patients (from 25 to 20) and urologists (from 32 to 28).

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“The initial median scores for both physicians and patients reflect a high level of uncertainty surrounding the decision to pursue adjuvant therapy. The 4-point decrease in DCS score for the providers and the 5-point decrease among the patients were statistically significant and are considered clinically significant,” Dr. Gore told Urology Times.

Data on management recommendations for these men with high-risk pathologic features showed that observation was the default for providers and remained so across risk categories after the urologists knew the patients’ genomic classifier stratification. However, the genomic test results influenced recommendations for men across all risk categories, decreasing recommendations for adjuvant treatment given to low risk patients and increasing the percentages of intermediate- and high-risk patients receiving a recommendation for adjuvant treatment.

Based on review of clinical characteristics alone, urologists recommended adjuvant treatment to only 12% of men overall and to 10% of men subsequently categorized as low risk by the genomic classifier, 18% of those in the intermediate-risk group, and 11% of those with a high-risk test result. After providers reviewed the genomic test results, a recommendation for adjuvant treatment was given to only 4% of men in the low-risk group, but to 25% of those categorized as having intermediate risk for progression and to 40% of those in the high-risk group.

“Adding the genomic classifier results to the decision-making process clearly impacts providers’ recommendations,” Dr. Gore said.

“The study is also investigating how the genomic classifier test changes patient treatment plan choices and quality of life, and those data are being analyzed.”

Several of Dr. Gore’s co-authors have a financial or other relationship with GenomeDx Biosciences and/or certain pharmaceutical or diagnostic testing companies.

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