Fertile Genomic Ground Leads to Growth of Technology, Knowledge
As medical oncology harvests the advantages of this fertile genomic age, so do the associated therapies that benefit cancer patients. Radiation oncology has sprouted some new opportunities for improved patient care and outcomes, now ripening with the help of technology and research.
Adam Dicker, MD, PhD, Professor and Chair of the Department of Radiation Oncology at Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, offers some insights into specific areas in which radiation oncology is seeing fresh growth.
The Heft of Genomics
“Genomics and molecular signatures are beginning to impact systemic therapies with the use of radiation,” Dicker told OT. He used the example of prostate cancer to clarify his assertion. “In the world of prostate cancer there are companies … that are seeking or already have FDA approval for genomic tests and the technologies built on each company’s ‘signature.’” These signatures are keyed to determining something specific, such as which patient has a more-aggressive disease or a less-aggressive disease, or will develop metastasis in five years, etc., he explained.
Dicker and colleagues at Jefferson have been working with GenomeDx (whose signature addresses the five-year probability of metastasis) on a controversial topic that taps into this new genomic enlightenment.
“When men with advanced diseases have positive margins or other adverse features following surgery, there’s a debate as to whether they should receive adjuvant radiation therapy after they have healed,” Dicker explained. “Our group, led by Robert B. Den, MD, working with scientists at GenomeDx (whose prostate cancer test is FDA-approved and approved for reimbursement by CMS), took the metastasis signature and applied it by asking the question, ‘Can this help us determine who benefits from radiation therapy and who doesn’t benefit from radiation?’ It turns out that, yes, we can determine a group of men who, based on their genomic signature, will benefit from radiation therapy (PLoS One 2015 Apr 2;10(3):e0116866. doi: 10.1371/journal.pone.0116866.) And then we asked, ‘Can we use this to determine who benefits from immediate adjuvant radiation therapy or determine patients who can wait until their PSA goes up just a little bit after surgery (termed ‘salvage’)? And again, the answer is yes; the signature can help with that as well (J Clin Oncol 2015 Mar 10;33(8):944-51).”
Dicker said their research data, which has been validated with data from investigators at Johns Hopkins, Mayo Clinic, and Duke University, lead them to a clear belief that there is a group of men who, based on genomics, can be advised as to whether they can wait for, delay, or avoid radiation therapy, as well as those who need it sooner. “This is just one example where the intersection of genomics and radiation will allow more selective use of radiation,” said Dicker.