Despite science’s ability to develop sophisticated and targeted new drugs, predicting the effect of a drug in an individual is still maddeningly difficult. Not every drug works for everyone that takes it. Similarly, the very same drug can be well tolerated in some, but can cause intolerable side effects in others. So-called “targeted therapies” were supposed to improve our accuracy, by focusing on specific targets on cells. That’s been good – but not sufficient to make drug treatments more consistently effective. Pharmacogenomics is the relationship between your DNA and how your body responds to drugs: how they’re absorbed, how they work, and how they’re eliminated from the body. It has been heralded for some time as the white knight of drug therapy. The genome revolution was supposed to remove (or dramatically reduce) the uncertainty in medicine, telling us which drugs will work more effectively, and which we might want to avoid. And to some extent, the genome-based treatment era is already here. There are over 100 drugs approved by the Food and Drug Administration (FDA) now that include genomic information in their prescribing information. For a small number of drugs, genomic testing is warranted. Increasingly, genomic testing is more accessible, moving from the research bench directly into retail pharmacies for sale when you pick up your prescription. Given pharmacies have a less-than-stellar record of selling laboratory testing that isn’t validated or even useful, I was immediately skeptical when I saw a new story on pharmacy-based genomic testing. Titled “Your pharmacist’s secret weapon: How your DNA can help perfect your medication,” it appeared in last week’s Globe and Mail: (more…)
Posts Tagged genetic testing
One size rarely fits all. Most medical knowledge is derived from studying groups of subjects, subjects who may be different in some way from the individual who walks into the doctor’s office. Basing medicine only on randomized controlled studies can lead to over-simplified “cookbook” medicine. A good clinician interprets study results and puts them into context, considering the whole patient and using clinical judgment to apply current scientific knowledge appropriately to the individual.
CAM practitioners claim to be providing individualized treatments. Homeopaths look up symptoms like “dreams of robbers,” “sensation of coldness in the heart,” and “chills between 9 and 11 AM” in their books, and naturopaths quiz patients in great depth about their habits and preferences; but they don’t have a plausible rationale for interpreting the information they gather. And they have not been able to demonstrate better patient outcomes from using that information.
A new concept, “precision medicine,” was recently featured in UW Medicine, the alumni magazine of my alma mater, the University of Washington School of Medicine. Precision medicine strives to provide truly individualized care based on good science. It identifies the individual variations in people that make a difference in our ability to diagnose and treat accurately. Peter Byers, MD, director of the new Center for Precision Diagnostics at the University of Washington, calls it “the coolest part of medicine.” (more…)
This will be a departure from my usual posts. Several announcements in the news and medical journals have caught my attention recently, and as I delved into the details, I thought I would share them with our SBM readers. Topics include AIDS cures, the continuing danger of polio, eating nuts for longevity, racial differences in vitamin D, and the use of pharmacogenetic testing to guide the dosage of anticoagulant drugs. They are all examples of science-based medicine in action.
Have patients been cured of AIDS?
I read that the HIV virus had returned in patients thought to have been cured by bone marrow transplants, and I mistakenly thought they were referring to the original claim of cure I had read about. Nope, that one still stands. (more…)
We are not alone. Walt Whitman didn’t know how right he was when he said, “I contain multitudes.” The microbes on and in our bodies outnumber our own cells 10:1. Perhaps that creeps you out. Perhaps that makes you curious to know just who all these billions of creatures are that are using your body for a home and a transportation device.
For just $89 you can learn what’s in your gut, nose, mouth, skin, genitals…or sample anything!
The offer comes from uBiome, a “citizen science startup” that has scientific goals somewhere down the line, but for the moment is happy to just provide a personal service, to sequence your microbiome and tell you how you compare to others. The current utility of this offering is questionable. It’s just not ready for prime time. (more…)
I had been debating whether to blog about Angelina Jolie’s announcement last week in a New York Times editorial entitled My Medical Choice that she had undergone bilateral prophylactic mastectomy because she had been discovered to have a mutation in the BRCA1 gene that is associated with a very high risk of breast cancer. On the one hand, it is my area of expertise and was a big news story. On the other hand, it’s been nearly a week since she announced her decision, and the news story is no longer as topical as it was. Also, I’ve already written about it a couple of times on my not-so-super-secret other blog, making the division of blogging…problematic. So, if some of this is a bit repetitive to those who are also fans of my more—shall we say?—insolent persona, I apologize, but try to be patient. I will be doing more than just rehashing a couple of posts from last week (although there will unavoidably be at least a little of that), because there have been even more examples of reactions to Jolie’s announcement that provide what I like to consider “teachable moments.” I will start by asserting quite bluntly that in my medical opinion, from the information I have available, Angelina Jolie made a rational, science-based decision. How she went about the actual mechanics might have had some less than scientific glitches along the way (more about that later), but the basic decision to remove both of her breasts to prevent breast cancer associated with a BRCA1 mutation that she carried was quite reasonable and very defensible from a scientific standpoint.
One advantage of waiting nearly a week to write about this story is that it provided me with the opportunity to sit back and observe the reactions that Jolie’s decision provoked. One thing that I really didn’t expect (although in retrospect maybe I should have) is the pure denialism on display that genes have any effect whatsoever on cancer. I say “in retrospect I should have” because I’ve written at least a couple of times before about how quacks use and abuse the term “epigenetics” in the same way that they abuse the word “quantum” and how they seem to believe that wishing makes it so (through epigenetics, of course!) to the point where they believe that genetics is irrelevant to cancer. Indeed, they go far beyond that, asserting that, in essence, environment is all. From what I’ve been reading thus far, the second strongest strain of reaction to Jolie’s announcement (after revulsion at the “mutilation” of women that it represented to certain quacks) is pure denial that mutations in BRCA1 and BRCA2 genes portend such a high risk of ultimately developing breast cancer. This denial is often accompanied by conspiracy mongering about BRCA1 and BRCA2 mutations being a “conspiracy” on the part of the “cancer industry” and Myriad Genetics & Laboratories, the company that holds the patents on BRCA1 and BRCA2, to increase genetic testing and preventative mastectomies. Myriad happens to have a complete monopoly on BRCA1 and BRCA2 testing because of this patent and has been criticized for its high prices and stifling of competition. There is currently a case before the U.S. Supreme Court regarding whether human genes are patentable under the law. I’m not a big fan of Myriad, and I’ll tell you why later. (Not that it matters; I’m stuck with them for now.) My personal distaste for Myriad Genetics aside, this sort of conspiracy mongering is part and parcel of the quack approach to denying the significance of BRCA1 mutations.
This denial is usually coupled with confident blather that Angelina Jolie didn’t need to undergo “disfiguring” surgery to prevent BRCA1-associated breast cancer but instead could have achieved the same—or even better!—risk reduction if only she had used this magic herb or that miracle supplement and making certain “lifestyle” changes. It’s utter nonsense, of course, but it’s everywhere.
Before I get to the reactions to Jolie’s announcement, let’s first take a look at what she did, why, and the science behind it.
I intended to read Sam Kean’s new book The Violinist’s Thumb: And Other Lost Tales of Love, War, and Genius as Written by our Genetic Code just for fun. I was expecting a miscellany of trivia loosely gathered around the theme of DNA. But I found something much more worthwhile that I thought merited a book review to bring it to the attention of our readers. Kean interweaves entertaining stories into a somewhat disjointed but nonetheless valuable history and primer of genetics. The title refers to Paganini, whose DNA created the unusual joint flexibility that facilitated his unprecedented feats of virtuosity on the violin.
Eric Topol, MD, has written a book about the convergence of the digital revolution and medicine. It is full of fascinating information and prognostication, but I wish he had given it a better title. He called it The Creative Destruction of Medicine: How the Digital Revolution Will Create Better Health Care. Medicine will not and cannot be “destroyed.” It will be improved and transformed, perhaps, but not destroyed. And any new developments will have to be evaluated for safety and effectiveness by the good old time-tested methods of science.
The future world of medicine is really exciting: science fiction is becoming real. As I read Topol’s book I serendipitously found it paraphrased by a character in another book I was reading, Chop Shop, by Tim Downs.
I see a world where no one ever dies from an adverse drug reaction; where physicians have an entire range of medicines to choose from to treat a deadly disease; where medications target tumors like smart bombs and leave surrounding tissues unharmed; where genetic susceptibility to disease can be determined in childhood, and possibly even prevented.
(If you haven’t yet discovered Downs’ hilarious “Bug Man” detective series about a crazy forensic entomologist, you have a treat in store.)
But back to non-fiction. Our world is changing almost too rapidly to comprehend: the Internet reaches everywhere, and there are far more mobile phones in the world today than toilets. We have hardly begun to tap the current potential of new technologies, and unimagined further developments await us. Topol is a qualified guide to this new world: he is a respected cardiologist and geneticist who ha s been on the forefront of wireless medicine and who was a major whistleblower in the Vioxx fiasco. He knows whereof he speaks, and he writes lucidly and accessibly.
Dr. H. Gilbert Welch has written a new book Over-diagnosed: Making People Sick in the Pursuit of Health, with co-authors Lisa Schwartz and Steven Woloshin. It identifies a serious problem, debunks medical misconceptions and contains words of wisdom.
We are healthier, but we are increasingly being told we are sick. We are labeled with diagnoses that may not mean anything to our health. People used to go to the doctor when they were sick, and diagnoses were based on symptoms. Today diagnoses are increasingly made on the basis of detected abnormalities in people who have no symptoms and might never have developed them. Overdiagnosis constitutes one of the biggest problems in modern medicine. Welch explains why and calls for a new paradigm to correct the problem. (more…)
A topic of growing interest (and concern) at SBM is laboratory and diagnostic test pseudoscience. Bogus tests are everywhere, and Kimball Atwood recently discussed several of them. But over the past several years, diagnostic tests have emerged that appear to be science-based and offer gene-level insights into your health. And these tests don’t even require a physician’s visit – just a swab of saliva and a credit card get you reams of information on your genetics, traits, and risks of dozens of diseases. It looks like the ultimate in consumer health information, with the potential to offer truly personalized treatment strategies. Companies like 23andme, deCODEme, and Navigenics all promise “genetic insights” to improve your health. How could this information be anything but helpful?
Personalized medicine describes medical practices that use information about a person’s genes, proteins, and environment to prevent, diagnose and treat disease. Science-based practice has routinely incorporated environmental advice (e.g., diet and exercise) into medical management. And there are a number of genetic tests in routine use that are well established, clinical validated, and are highly predictive of future outcomes, such as tests for Huntington’s disease and hereditary breast cancer.