Geographic variation of decipher genomic classifier in patients with early prostate cancer.

Abstract

376 Background: External factors such as environmental or lifestyle-related exposure may influence genomic composition of cancer, and therefore its progression and outcome. Thus geographic data is of importance. Decipher is a gene expression classifier used in risk stratification of early non metastatic prostate cancer. Currently, there are no data reporting geographic variation of the test. We aimed to analyze Decipher genomic score results among Israeli patients, in comparison to American patients. Methods: The Decioher database (Decipher Biosciences Inc) contains data from patients who have given consent for broad data-sharing. We identified and analyzed Decipher test results ordered among Israeli patients with localized prostate cancer. Matched analysis to the US population was done. Results: 144 patients (median age 69.5, range 64-74) were included in the present analysis. The clinical NCCN risk grouping was low in 42.4% (n=61), favorable intermediate in 38.9% (n=56), unfavorable intermediate in 17.4% (n=25), and high risk in 1.4% (n=2). Physicians primarily obtained Decipher for low-intermediate NCCN risk. Median Decipher score was 0.57 (Q1 0.385, Q3 0.823). Decipher risk grouping was low in 38.1% (n=61), intermediate in 16.9% (n=27), and high in 45% (n=72). Median Decipher score increased with Grade Group. 46% of NCCN low risk patients had a higher risk as per Decipher. 82% of NCCN favorable intermediate and unfavorable intermediate risk were reclassified to lower or higher risk. 9% of NCCN high risk patients had a lower risk as per Decipher. The present study cohort had a higher proportion of higher Decipher scores than observed in similar grade US population (n=43065) in the Decipher database (Median 0.43, Q1 0.27, Q3 0.66; 52%/18%/30% with low/intermediate/high risk). Conclusions: The preliminary results of the present study suggest a higher proportion of high risk Decipher among Israeli patients with early prostate cancer. These results should be interpreted cautiously. The study and further data collection are ongoing.