ALEXANDRIA, Va. – Analysis of free-floating cancer DNA from blood samples has yielded leads for new prostate cancer treatment targets. Using a commercially available “liquid biopsy” test in patients with advanced prostate cancer, researchers found a number of genetic changes in cell-free, circulating tumor DNA (ctDNA). Cell-free ctDNA is tumor DNA that is circulating freely in the patient’s bloodstream. The study will be presented at the upcoming 2017 Genitourinary Cancers Symposium in Orlando.
Cell-free ctDNA provides comprehensive information about all the different genetic changes in the tumor. Today, treatments can sometimes be tailored to the genetic changes in a tumor, but these changes evolve over time. The cell-free ctDNA tests can be used to track new genetic changes, and this information can be used to stop treatment to which resistance is emerging and to switch the patient to another treatment.
In the study, researchers found genetic changes linked to poor outcomes, as well as changes that appear to arise as tumors become resistant to therapy. The changes in ctDNA found by the blood tests were similar to those previously reported in analyses of tumor tissue specimens, suggesting that ctDNA testing may be a viable alternative to tissue biopsy.
“This circulating tumor DNA test is now a valuable research tool to discover new molecular targets,” said lead study author Guru Sonpavde, MD, an associate professor of medicine at the University of Alabama in Birmingham, AL. “Eventually, it may also serve as a non-invasive alternative to the traditional tumor biopsy in cases where tissue biopsy is not safe or feasible. However, we’ll need a controlled, prospective clinical trial to confirm that selecting treatment based on the molecular information from this blood test improves patient outcomes.”
The genes that were most often mutated included TP53 (36%); AR (22%); APC (10%); NF1 (9%); EGFR, CTNNB1 and ARID1A (6% each); and BRCA1, BRCA2, and PIK3CA (5% each). The most common genes with increased copy numbers were AR (30%), MYC (20%), and BRAF (18%) [increased cancer gene copy number can lead to overabundance of proteins that drive cancer growth]. Currently, there are no approved treatments for prostate cancer that target these specific genetic mutations, although several are being tested in clinical trials.
In the group of patients who underwent periodic blood tests, new changes in AR gene were particularly common. According to the researchers, this finding suggests that developing treatments that target AR mutations may hold promise.
This study was unfunded; de-identified data were provided by Guardant Health.
The above post is reprinted from materials provided by American Society of Clinical Oncology (ASCO). Note: Materials may be edited for content and length.
Disclaimer: DoveMed is not responsible for the adapted accuracy of news releases posted to DoveMed by contributing universities and institutions.
and connect with fellow professionals
At DoveMed, our utmost priority is your well-being. We are an online medical resource dedicated to providing you with accurate and up-to-date information on a wide range of medical topics. But we're more than just an information hub - we genuinely care about your health journey. That's why we offer a variety of products tailored for both healthcare consumers and professionals, because we believe in empowering everyone involved in the care process.
Our mission is to create a user-friendly healthcare technology portal that helps you make better decisions about your overall health and well-being. We understand that navigating the complexities of healthcare can be overwhelming, so we strive to be a reliable and compassionate companion on your path to wellness.
As an impartial and trusted online resource, we connect healthcare seekers, physicians, and hospitals in a marketplace that promotes a higher quality, easy-to-use healthcare experience. You can trust that our content is unbiased and impartial, as it is trusted by physicians, researchers, and university professors around the globe. Importantly, we are not influenced or owned by any pharmaceutical, medical, or media companies. At DoveMed, we are a group of passionate individuals who deeply care about improving health and wellness for people everywhere. Your well-being is at the heart of everything we do.
0 Comments
Please log in to post a comment.