If a prostate biopsy detects cancer, tissue from the gland will be analyzed in a lab to estimate how likely it is to spread and turn deadly. But biopsy results can sometimes misclassify tumors as low or high risk, and this uncertainty dissuades many good candidates for active surveillance from choosing that treatment strategy.
The National Comprehensive Cancer Network (NCCN) suggests that these molecular tests, which analyze biopsy specimens, may provide valuable additional information for men considering active surveillance who have a life expectancy of at least 10 years and have been diagnosed with low-risk tumors. (NCCN guidelines state that some men with less worrisome intermediate tumors may consider these tests, too.)
Decipher. There are two versions of the Decipher test, which analyzes 22 genes that appear to promote the spread of prostate cancer (metastasis).
The Decipher Biopsy estimates a man’s risk for future diagnosis of high-grade cancer, developing metastasis within five years, or dying of prostate cancer in 10 years. Data on the Decipher Biopsy’s role in helping men to decide whether to choose active surveillance is limited, however.
A second test, the Decipher Prostate Cancer Classifier, is designed to predict the likelihood that a patient will develop tumor metastasis following radical prostatectomy, and thus benefit from further therapy, such as adjuvant radiation.
Oncotype DX Prostate. This test analyzes the activity, or expression, of 12 genes associated with aggressive prostate cancer to produce a Genomic Prostate Score (GPS) from 0 to 100; higher scores suggest more aggressive tumors. A 2016 study found that adding GPS to other traditional clinical data more than doubles the portion of men who are appropriate candidates for active surveillance.
Prolaris. In aggressive cancers, tumor cells divide rapidly. The Prolaris Test assesses the expression of 46 genes, including 31 that regulate how fast cells proliferate, or spread.
This test produces a cell-cycle progression (CCP) score, which reflects a patient’s 10-year risk for dying of prostate cancer if he opts for active surveillance or prompt treatment. A 2012 study found that the CCP score predicted the risk for dying of prostate cancer more accurately than other clinical factors, including a man’s Gleason score, baseline PSA level, and tumor stage.
Promark. One of the newer tests on the market, Promark uses imaging to examine prostate tissue for the presence of eight proteins found in aggressive tumors. The test produces a score falling within a range from 0.0 to 1.0, with scores of 0.33 or higher considered cause for concern.