Lead author Dr. Matthew R. Cooperberg of the University of California, San Francisco said the test could aid in determining which men are suitable for active surveillance.
Prostate cancer often grows slowly, and many of the 250,000 U.S. men diagnosed annually never need treatment, which typically involves surgery, radiation or both. However, most patients with low-risk prostate cancer in the United States immediately undergo treatment, Cooperberg said.
Active surveillance involves closely monitoring a patient's condition through serial prostate specific antigen screening and prostate biopsies, but otherwise the disease is not treated unless tests show the condition is getting worse. Active surveillance is not entirely benign -- biopsies are uncomfortable and carry a risk of bleeding and infection.
The independent clinical study of 395 men validated the Oncotype DX Genomic Prostate Score, a biopsy-based pretreatment tool of Genomic Health, Inc. as a predictor of high grade or extracapsular prostate cancer.
"With the new test, we can more confidently recommend active surveillance when it is appropriate," Cooperberg said in a statement. "And patients through active surveillance can avoid or delay surgery or radiation for their condition."
The findings were presented at the American Urological Association's annual meeting in San Diego.