These markers may lead to the development of a urine test that could complement – or perhaps even replace – prostate biopsy for predicting disease aggressiveness and progression.
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.
Study principal investigator Daniel Lin, M.D., an associate member of the Fred Hutchinson Cancer Research Center’s Public Health Sciences Division, presented these findings today at the 2012 Genitourinary Cancers Symposium in San Francisco.
“Prostate biopsies are invasive and don’t always pick up all of the cancer. If a urine-based diagnostic test could be developed that could predict aggressive disease or disease progression as well as or better than a biopsy, 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.
The findings being presented today 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 a total of 1,000 men and follow them for at least five years.
“We know that over half of the 240,000 men diagnosed with prostate cancer each year have low risk cancers. Of these 120,000 men, most are treated when perhaps only 5-10% need it. When we’re done with this study, the incredible 1,000 men in this study may help us avoid treatment for over 100,000 men each year in the U.S.”, said Ian M. Thompson Jr, M.D., director of the Cancer Therapy and Research Center at the UT Health Science Center and co-principal investigator of the study.
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 accurately mirrored these correlates of disease aggressiveness were:
PCA3 – a non-coding RNA that is only found in prostate tissue and has better sensitivity and specificity than PSA in predicting the presence of prostate cancer; and
TMRPSS2-ERG – the fusion of TMRPSS2, a gene that regulates androgen production, with ERG, an oncogene found in about half of all prostate cancers. Such genetic rearrangements are thought to play a role in the development of the majority of prostate cancers.
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.
The Canary Foundation and the Early Detection Research Network (EDRN) of the National Cancer Institute funded the study, and the EDRN Data Management Coordinating Center is based in the Hutchinson Center’s Public Health Sciences Division under the direction of biostatistician Ziding Feng, Ph.D. Gen-Probe Inc. provided the biomarker analysis.
Other lead researchers on the study include Peter S. Nelson, M.D., a member of the Hutchinson Center’s Human Biology and Clinical Research Divisions and head of the Canary Prostate Team; James D. Brooks, M.D., an associate professor of urology at Stanford School of Medicine; Peter Carroll, M.D., M.P.H., professor and chair of urology at University of California, San Francisco; Martin Gleave, M.D., distinguished professor and director of research in the Department of Urologic Sciences at the University of British Columbia; Raymond S. Lance, M.D., an associate professor of urology at Eastern Virginia Medical School; Martin G. Sanda, M.D., associate professor and director of the Prostate Care Center at Beth Israel Deaconess Medical Center at Harvard University; and John T. Wei, M.D., M.S., professor of urology and associate chair of research at the University of Michigan Medical School.
The Cancer Therapy & Research Center (CTRC) at The University of Texas Health Science Center at San Antonio is one of the elite academic cancer centers in the country to be named a National Cancer Institute (NCI) Designated Cancer Center, and is one of only four in Texas. A leader in developing new drugs to treat cancer, the CTRC Institute for Drug Development (IDD) conducts one of the largest oncology Phase I clinical drug programs in the world, and participates in development of cancer drugs approved by the U.S. Food & Drug Administration. For more information, visit www.ctrc.net.
Contact: Elizabeth Allen, CTRC, 210-450-2020