Urine test helps predict prostate cancers that are likely to be aggressive and life-threatening among men who take a watchful waiting, reveals study.
Ultimately, these markers may lead to the development of a urine test that could complement prostate biopsy for predicting disease aggressiveness and progression.Study principal investigator Daniel Lin, M.D., an associate member of the Hutchinson Center's Public Health Sciences Division, will present these findings today at the 2012 Genitourinary Cancers Symposium of the American Society of Clinical Oncology in San Francisco.
Advertisement"Prostate biopsies are invasive and don't always pick up all of the cancer. Post-digital-rectal exam 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," said Lin, who is also an associate professor and chief of urologic oncology at the University of Washington Department of Urology.
Lin leads a nationwide consortium of eight institutions called the Canary Prostate Active Surveillance Study, an endeavor dedicated to identifying and validating biomarkers of high-risk prostate cancer.Because many prostate cancers are slow growing and never become life threatening, many men with early stage prostate cancer choose active surveillance - delaying treatment while closely monitoring to see whether the cancer progresses.Two urine-based biomarkers were found to correlate with indicators of aggressive disease: tumor volume (the number of biopsy samples that contain cancer) and Gleason score (predicting the aggressiveness of cancer by how it looks under a microscope).
The markers that mirrored these correlates of disease aggressiveness were:
- PCA3 - a non-coding RNA that is found at high levels in prostate cancer relative to benign prostate cells; and
- TMPRSS2-ERG - 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.