Sources of current medical information concerning prostate cancer are listed on this website under the section Medical Resources. Recently, a new August 2011 electronic newsletter entitled NewsPulse was received from the Prostate Cancer Foundation. The issue contained very current information on specific diagnostic methods, biomarkers for cancer detection, targeted therapies and drugs under development, nutrition and genetics. One example follows below. Their e mail address is info@pcf.org. I would strongly recommend a subscription.
Biomarkers in Urine for the Detection of Prostate Cancer.
Biomarkers are usually genes, gene products or proteins and are found in various body fluids (blood, urine, cerebrospinal fluid). Their presence, absence and quantities are measured and used to diagnose various diseases and their stages. An example is prostate-specific antigen or PSA used to detect prostate conditions. The availability of an easy-to-use urine test that is specific in identifying the presence of cancer has the potential to eliminate thousands of unnecessary prostate biopsies in the U.S. each year. Thus the benefits of such biomarker tests below include identifying which patients actually require biopsies.
The June 1st, 2011 issue of the Johns Hopkins Health Alerts and the August issue of NewsPulse both describe two new biomarkers found in urine which may potentially be useful in detecting prostate cancer as opposed to other non-cancerous prostate conditions such as BPH (benign prostatic hyperplasia or enlarged prostate). The two specific biomarkers are: a) prostate cancer antigen or PCA3, which is expressed at high levels in 95 percent of prostate cancer patients; and, b) the DNA marker TMPRSS2:ERG gene fusion, a hybrid gene made from two previously separate genes, specifically the ERG and TMPRSS2 genes. This DNA marker is present in 50 percent of prostate cancer patients. The presence of this gene fusion is “thought to promote the development of prostate cancer and possibly a more aggressive form of the disease.”
PCA3 is made by a specific gene that produces the protein in 60-100 times more abundance in prostate cancer cells as compared to non-cancerous ones. According to Johns Hopkins, in order to be most predictive, the test for PCA3 should be done in conjunction with a digital rectal examination. PCA3 testing would not replace the usual PSA blood test but would help to either confirm or rule out the prospect of cancer in men with elevated PSA levels.
Patients with high levels of these biomarkers have been shown to have a 70 percent chance of having cancer with a 40 percent of it being a high grade cancer. There is also an association between test results and the size of the tumor in patients who do have cancer. It will take some time before the combined urine-based assay is widely introduced into practice. However, NewsPulse reports that the “University of Michigan has been offering the PCA3 test alone since earlier this year. They expect to be offering it in combination with TMPRSS2:ERG by the end of this year under a license agreement with GenProbe. Another trial using the combined assay will soon be conducted in cooperation with the Early Detection Research Network (EDRN). EDRN, an initiative of the National Cancer Institute (NCI), brings together dozens of institutions to help accelerate the translation of biomarker information into clinical applications and to evaluate new ways of testing cancer in its earliest stages and for cancer risk.”
“Once the University of Michigan begins offering the combined TMPRSS2:ERG/PCA3 test, physicians can send urine samples for analysis until the combined test is more widely available. For more information on this, men with questions about prostate cancer screening should speak to their doctors or call the U-M Cancer AnswerLine at 800-865-1125.”
As previously stated, the contents of this website are intended solely for information and encouragement. All medical decisions and actions should be made in consultation with a physician or appropriate medical personnel.