Shining a light on genomic somatic testing vs. germline genetic testing: We patients need help
Plus join Dr. Todd Morgan's AnCan webinar on July 31 on genomics
By Howard Wolinsky
When it comes to tissue-based genomic or somatic testing, patients with low-risk to favorable intermediate-risk prostate cancer are largely in the dark. Likewise, DNA or germline testing—looking at our inherited genes—is also confusing.
I see in support groups I attend that men generally are not clear about the differences between DNA testing of their own genes and somatic or genomic testing of their prostate lesions. (Yes, our tumors have their own DNA, which can be used to determine whether we should consider active surveillance, close monitoring with PSA blood level tests, MRIs and biopsies, or more aggressive treatment.)
Michael S. Leapman, MD, associate professor of urology, clinical program leader, Prostate & Urologic Cancers Program, Yale Cancer Center, conducted a study that was very revealing about how little we patients know about this testing.
His research shows that a physician's recommendation primarily drives a patient's decision to undergo genomic testing. In some cases, the physician entirely influences this decision.
Also, in some cases, the physician only explains the option iafter testing occurred, he found.
Let me say that again for emphasis: In some cases, patients only receive explanations after testing occurred. Yikes. I guess that saves time.
Leapman’s study focused on patients with low- or favorable to intermediate-risk prostate cancer managed with AS. The study population included those who received genomic testing as part of routine clinical care. He also deliberately oversampled traditionally underrepresented Black and Latino men.
Some patients are not sufficiently informed about this test at any point in the decision-making process, Leapman said.
In some cases, genomic testing is introduced prior to its administration, and the choice to administer it is a joint decision between patients and physicians, he said.
That’s how it should be done.
Although patients generally understood the purpose of genomic testing in identifying risk status, many did not understand the difference between genomic testing and genetic testing, Leapman said.
We’re not alone. This may be true for some health practitioners, too.
Genomic or somatic tests measure mRNA expression in tissue samples, but many patients believe that the test measures heritable characteristics or genetic predispositions, he explained.
In cases where the physician provided an explanation, some felt that this communication was still inaccessible and insufficient, the Yale researcher found.
Again, genomic tests measure the DNA in tumors, which is separate from our own. DNA testing looks at our i DNA for inherited markers relevant to prostate cancer such as BRCA and ATM (not the automated teller machine at your bank).
You actually can blame the DNA markers on your parents. DNA testing can be done with a spit or blood same. No biopsy is required,
In localized cancer, somatic tumor genomic testing can be used to determine whether a man is able to safely choose active surveillance over definitive therapy such as surgery or radiation. The testing has other purposes in men with advanced cancers.
In localized cancer, DNA testing roots out genetic mutations that can put a man at increased risk.
Say a man’s biopsy showed he a great candidate for AS with s Gleason. But his DNA test shows he has inherited the BRCA gene.
I know a guy who looked perfect for AS, but he underwent DNA testing and found he—like his dad and sister—was a carrier of BRCA 2. He underwent a prostatectomy that revealed he had a Gleason 9 hidden in his prostate gland.
Genetics showed its value.
Leapman said doctors can lead patients out of the darkness with more structured interviews on testing and giving us the opportunity to ask questions. Also, I think we need to come into the doctor’s office better prepared when we can.
Leapman talks about his study here: https://www.onclive.com/view/dr-leapman-on-factors-influencing-the-decision-to-undergo-genomic-testing-in-prostate-cancer
Dr. Todd Morgan, urological surgeon, genomics researcher and Chief of Urologic Oncology at the University of Michigan (Go Blue!), told me in a recent interview about germline DNA vs. somatic genomics: “I don't think patients inherently know the difference. If we start using the terminology without explaining it, there is no reason to expect that patients are going to understand what we're talking about. Even other medical providers, who don't really work closely in this space, may not be familiar with which tests are looking at things that are inherited versus not. I think that's a really important distinction.”
In his practice, he said he attempts to be “really, really clear with the difference” between genetic and genomic testing.
“And it's so important when we are looking at inherited DNA testing because it has an impact beyond that person and their cancer. And so, this is something that I talk a lot about is that when we're recommending germline testing for patients. It can't just be like ordering a hematocrit. It can't be just like ordering a urine culture,” he said. “There are really clear guidelines for how patients should be counseled before undergoing that test.”
A major problem in genetic testing is that there is a widespread shortage of genetic counselors to explain tests, which puts more of the burden of pre-testing counseling on the backs of the clinicians.
Go to AS 101 at https://aspatients.org/a-s-101/ to learn more about genetic pre-testing and genetic testing.
I can tell you counseling helps a lot. I found that myself when I underwent the free Color test in the Promise study for prostate cancer. You can read about my experience here:
https://home.color.com/pharma/promise?utm_source=wondros&utm_medium=banner&utm_campaign=join_u
To sign up for the free PROMISE study, go to: https://home.color.com/pharma/promise?utm_source=wondros&utm_medium=banner&utm_campaign=join_us
Dr. Todd Morgan to genomic rescue in July 31 webinar at AnCan
By Howard Wolinsky
Dr. Morgan is coming to the rescue with an AnCan webinar at 8 p.m. Eastern July 31 to help us find our way through the genetics and genomics jungle.
To register for the program, entitled “How and why PCa genomic tests work ... What's Inside the Black Box?", go to: https://tinyurl.com/ancanpcagenwebinar
The program is aimed at the full spectrum of patients with prostate cancer, from low-risk to high-risk.
Morgan will cover the difference between inherited and somatic testing, who should undergo genomic testing, and his randomized trial comparing the leading genomic tests, Decipher, Prolaris, and Oncotype DX.
Please send your questions, comments and feedback to: joeg@ancan.org