Originally published Oct. 7.
NEW YORK (GenomeWeb) – Genomic Health's multi-gene expression prostate cancer test assesses adverse pathology at the time of surgery and is an independent predictor of increases in prostate cancer antigen after surgery, researchers last week announced at a major European medical conference.
The latest clinical validation trial involved just over 400 patients from the multi-center national database at the Uniformed Services University of the Health Sciences' Center for Prostate Disease Research. For the study, researchers analyzed archival tissue samples from 402 men treated with radical prostatectomy for very low, low, or intermediate risk of prostate cancer at two US military care facilities between 1990 and 2012. Of these patients, 82 were African-American.
Based on the data researchers presented at the European Society for Medical Oncology Congress last week, Oncotype DX Genomic Prostate Score predicts whether men with newly diagnosed low- or intermediate- risk disease are likely to have adverse pathology at the time of surgery or are at long-term risk for biochemical recurrence after surgery. "These new results provide the first validation of our test's ability to predict biochemical recurrence and a second, independent validation of its ability to predict adverse pathology," Phil Febbo, Genomic Health's chief medical officer, said in a statement.
Significantly, researchers found that in this study, the test predicted accurately patient outcomes in Caucausians and African-American men. "The analysis showed that GPS distribution was very similar between African-American and Caucasian patients," Genomic Health said in a statement. The data also showed that the test significantly predicted the risk of metastatic prostate cancer recurrence, which Genomic Health highlighted as notable since the chance of metastases in low- or intermediate-risk patients is so low.
Finally, the latest study showed that certain gene groups in GPS, such as those involved in androgen signaling or stromal response, are "more strongly associated" with biochemical recurrence. Meanwhile, genes in all four pathways gauged by GPS significantly predict adverse pathology.
The prostate cancer test measures the expression of 17 genes across four biological pathways involved in prostate cancer progression. The test yields a score for patients between 0 and 100, and this result may be combined with clinical factors to inform the risk of prostate cancer ahead of treatment.
This study on the prostate cancer test is in line with other recently published validation data. The company published three studies a few months ago in European Urology – two development trials and a third validation study conducted with Cleveland Clinic and the University of California, San Francisco. The development studies enabled Genomic Health to narrow down the panel of genes from 700 candidate markers to 17 genes. The third clinical validation study involving nearly 400 men showed the test could accurately determine which patients were at high risk of prostate cancer, and the score held up as a significant prognostic tool in multivariate analysis against standard clinical measures.
These studies have bolstered uptake of the prostate cancer test, which Genomic Health launched in May 2013. In August, Genomic Health told investors during an earnings call that approximately 900 urologists had ordered the prostate cancer test, and more than half had reordered it.