Screening and Treatment News Items from the Prostate Cancer Research Institute (PCRI) Highlights

The Prostate Cancer Research Institute publishes a monthly periodical called “Insights”. At the end of 2013, they also updated their user-friendly and searchable website, http://www.pcri.org. The February 2014 issue of Insights contained considerable information which I will briefly summarize. I encourage you to see the articles in their entirety.

First, Dr. John Davis from MD Anderson Cancer Center describes the “Prolaris Test for Prostate Cancer” which serves as an introduction to this novel genomic test and its role in improving clinical decisions about treating prostate cancer. Prolaris is a test performed on biopsy tissue that looks at the average expression of 31 Cell Cycle Progression (CCP) Genes, which are involved in telling a cell to divide in two. Such a test result can be grouped with other factors to help determine the potential prostate cancer aggressiveness or lack thereof. The test can be helpful in men who are interested in active surveillance but may not have low-grade, low-volume disease. It can help define the risk of cancer-related mortality if left untreated. The test is expensive (around $3400) and insurance coverage can vary.

Secondly, an article by Dr. Mark Scholz summarizes presentation highlights from a recent Prostate Cancer Foundation retreat. One presentation described the discovery of a new gene product called SCHLAP-1 that can help predict the likelihood of future metastases. SCHLAP-1 may have the same predictive power as a Gleason score in distinguishing low-grade from high-grade disease. Another presentation discussed the role of PSA decline as a measure of treatment effectiveness. PSA can be notably inaccurate as demonstrated with Provenge and Xofigo as neither causes a consistent decline in PSA though both have been shown to improve survival. Dr. Howard Scher of Sloan-Kettering described studies that rely on measuring a decline in circulating tumor cells (CTC) in response to therapy as an accurate method for early prediction of long-term survival. Dr. Scher combines CTC levels with measurement of an enzyme called lactate dehydrogenase (LDH) to differentiate patients into low, intermediate or high risk categories. The system has been tested and validated to predict survival and could be used by the FDA for evaluating new drugs according to Dr. Scher. Dr. Victor Velculescu from Johns Hopkins presented his work which suggests that the presence or absence of microscopic residual disease (micro-metastases) could be detected with new genetic tests called genomic analysis. If a test could confirm that a patient was free of metastases, then long-term hormonal treatment might be unnecessary.

An effect called the Abscopal Effect states that radiation may actually stimulate one’s immune system according to Dr. Mark Scholz. Presently, little is known about how anti-cancer therapies such as radiation interact with immunotherapy in a clinical setting. Phoenix, AZ – based 21st Century Oncology is beginning a clinical trial designed to determine if radiation-induced tumor death augments the anti-tumor responses from Provenge. Patients treated with a combination of spot radiation and Provenge will have their tumor responses tracked with C11-acetate PET scans. See the article for details.

In an article named “A New Approach to Prostate Cancer Screening”, the authors suggest that “rather than doing an immediate biopsy, doctors should consider prostate imaging with multi-parametric MRI or Color Doppler Ultrasound. In experienced hands with state-of-the-art equipment, high grade cancer can be ruled out with 95 to 98% accuracy. And when imaging detects a high-grade lesion, a targeted biopsy directed specifically at the area of abnormality can be performed. If the scans show that no high-grade disease is present, the patient can forgo biopsy and simply monitor the situation with further PSA testing and, if necessary, consider additional imaging in six to twelve months.” The same issue contains an article called “What’s New in Prostate Cancer” by Dr. Stanley Brosman. He discusses the use of multi-parametric-MRI (mp-MRI) to see abnormalities suspicious for prostate cancer. mp-MRI does tend to miss cancers that are low-grade which may be a good thing. In experienced hands, the ability to detect Gleason score 7 or 8 tumors was 98% accurate and the ability to predict the absence of aggressive tumors was 91%. This technique also allows for a more targeted approach to doing a needle biopsy. The mp-MRI is also very useful for following prostate cancer patients who are on Active Surveillance. A  drawback is that a specific type of MRI, namely a 3-Tesla MRI, is needed in the hands of a highly trained radiologist.  The test is also currently expensive and may not be covered by all types of insurance.

Finally, medications to treat osteoporosis in men receiving hormone therapy have been widely used for years. It has now been learned that men who have bone metastases can have stabilization and regression of the tumor with the use of these agents. Denosumab (Prolia) and XGEVA are being used with good results. It was reported that the use of Denosumab (Prolia) may be a preventive agent and delay the onset of bone metastases in high-risk patients.