The two investigational urine-based biomarkers are associated with prostate cancers that are likely to be aggressive and potentially life threatening among men who take a "watchful waiting," or active-surveillance approach to manage their disease.

Investigators at the Fred Hutchinson Cancer Research Center (Seattle, WA, USA) coordinated a multicenter study of eight institutions called the Canary Prostate Active Surveillance Study (Palo Alto, CA, USA), an endeavor dedicated to identifying and validating biomarkers of high-risk prostate cancer. Two urine-based biomarkers were found to correlate with indicators of aggressive prostate cancer, the number of biopsy samples that contain cancer (tumor volume) and predicting the aggressiveness of cancer by how it looks under a microscope (the Gleason Score).

The findings were based on an interim analysis of data collected from 401 men who opted for active surveillance of their cancer. The study compared biomarker performance to clinical data collected at the time of study entry. Ultimately, the study aims to enroll 1,000 men and follow them for at least five years. The first marker that mirrored the correlates of disease aggressiveness was the prostate cancer antigen 3 (PCA3) that is a noncoding ribonucleic acid (RNA) that is found at high levels in prostate cancer relative to benign prostate cells. The second marker was the transmembrane protease, serine 2 - Ets Related Gene (TMPRSS2-ERG), which is the fusion of TMPRSS2, a gene that is regulated by androgens, with ERG, an oncogene. These genetic rearrangements are found in about half of all prostate cancers and are thought to play a role in prostate cancer development.

Daniel Lin, MD, the principal investigator said, "The ultimate goal is that men on active surveillance could use a test based on these biomarkers or others to complement biopsy and prostate specific antigen (PSA) data to indicate or rule out the presence of an undetected aggressive cancer or future development of aggressive cancer. Prostate biopsies are invasive and don't always pick up all of the cancer. Postdigital-rectal examination urine collection is much less invasive. If a urine-based diagnostic test could be developed that could help predict aggressive disease or disease progression that would be ideal.” The study was presented at the 2012 Genitourinary Cancers Symposium of the American Society of Clinical Oncology held February 2-4, in San Francisco (CA, USA).

Related Links:
Fred Hutchinson Cancer Research Center
Canary Foundation