Most often, men diagnosed with prostate cancer have a low risk of progression (LRP). However, some men have intermediate or high risk of progression (IHRP). Physicians tend to overtreat or undertreat patients because they do not have a reliable way to accurately determine the risk of progression. A new study published in Mayo Clinic Proceedings has provided a potential solution to this dilemma.
"We have discovered new molecular markers that can help guide men in their decisions about the course of their prostate cancer care," remarked George Vasmatzis, PhD, Co-Director of the Center for Individualized Medicine's Biomarker Discovery Program and lead author of the study. "Overtreatment has been an issue for the group of men that our study targets. We found that the presence of genetic alterations in low-risk cancer can help men decide whether treatment or active surveillance is right for them."
When the researchers conducted a needle biopsy of 154 frozen prostate gland specimens taken from 126 patients between 2001 and 2011 in order to identify chromosomal rearrangements, including abnormal junctions and copy number variations, they found that abnormal junctions did not differentiate LRP from IHRP. However, altered loci corresponding to genes involved in prostate cancer appeared more frequently in IHRP. In addition, copy number variations were a strong indicator of risk of progression.
The Gleason score, another indicator of progression, has a huge impact on prostate cancer treatments. Biopsy prostate tissue samples are given a grade from 1 to 5 based on how cancerous the cells look, with 1 being least cancerous and 5 being most cancerous. John Cheville, MD, Co-Director of the Center for Individualized Medicine's Biomarker Discovery Program and co-author of the study, emphasized the importance of copy number variations in relation to the Gleason score: "The needle biopsy procedure samples only a small portion of the tumor. It is not uncommon that a man with a Gleason pattern 3 on needle biopsy specimen harbors a higher-grade cancer next to the pattern 3 that was missed by the procedure. Therefore, if we identify these alterations in a Gleason pattern 3, there is a higher likelihood that Gleason pattern 4 is nearby."
This new method will offer a better course of treatment for patients, one that is designed to effectively treat the potential progression of the prostate cancer.
For More Information
Vasmatzis G, Kosari F, Murphy SJ, et al (2019). Large chromosomal rearrangements yield biomarkers to distinguish low-risk from intermediate- and high-risk prostate cancer. Mayo Clin Proc, 1(94):27-36. DOI:10.1016/j.mayocp.2018.06.028
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