Do Genomic Markers Correlate With Subclassification of High-Risk Prostate Cancer?
Posted: Monday, January 27, 2020
Although guidelines currently recommend a two-tiered system of subclassification for high-risk prostate cancer, Vinayak Muralidhar, MD, MSc, of the Dana-Farber Cancer Institute, Boston, and colleagues found that genomic markers of cancer risk may more accurately correlate with a three-tiered classification system: favorable high-risk, standard high-risk, and very high-risk disease. The findings, published in the International Journal of Radiation Oncology • Biology • Physics, appear to validate the prognostic utility of the three-tiered classification system.
The study team identified 3,220 patients with intermediate-risk (n = 2,000) or high-risk (n = 1,200) prostate cancer from a multi-institutional registry cohort. Based on previously published data, the researchers defined the three-tiered subclassification into favorable high-risk (cT1c, Gleason = 6, and PSA > 20 ng/mL or cT1c, Gleason 4 + 4 = 8, PSA < 10 ng/mL), very high-risk (cT3b-T4 or primary Gleason = 5), and standard high-risk (all others with cT3a, Gleason ≥ 8, or PSA > 20 ng/mL). Using genomic classifiers, the researchers determined whether high-risk genomic features were related to clinical subclasses of prostate cancer.
A high-risk Decipher score (determined from a 22-gene panel test) was found in 50.4%, 64.2%, and 81.6% of patients with favorable high-risk, standard high-risk, and very high-risk prostate cancer, respectively (P < .001). Of the 32 other genomic signatures, 29 showed a similar increasing trend across the three subclasses of high-risk disease (P < .05). Similarly, patients had a median of 4, 6, and 13 high-risk signatures across the three subclasses, respectively. Conversely, among patients who were classified with unfavorable intermediate-risk prostate cancer, 38.2% had a high-risk Decipher score, and the median number of high-risk signatures was three.
“Further research is needed to determine how best to incorporate these clinical and genomic risk stratification tools to tailor treatment for men with high-risk prostate cancer,” the researchers concluded.
Disclosure: For full disclosures of the study authors, visit redjournal.org.