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Archive for Diagnostic tests & procedures

Meet Your Microbes: uBiome Offers New Service

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…)

Posted in: Diagnostic tests & procedures, Medical Ethics

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Will Your Smartphone Become a Tricorder?

The Star Trek universe is a fairly optimistic vision of the future. It’s what we would like it to be – an adventure fueled by advanced technology. In the world of Star Trek technology makes life better and causes few problems.

One of the most iconic examples of Star Trek technology is the medical tricorder. What doctor has not fantasized about walking up to a sick patient, waving a handheld device over them, and then having access to all the medical information you could possibly want. No needle sticks for blood tests, no invasive tests, scary MRI machines, and no wait. The information is available instantly.

It’s clear that we are heading in that direction as technology progresses, but how close are we?

The Smartphone in Medicine
Many people in developed nations today are walking around with supercomputers in their pocket – their smartphone. Technological advances are often strange – the ones we anticipate seem to never come, but then life-changing technology creeps up on us.

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Posted in: Diagnostic tests & procedures, Medical devices, Science and Medicine

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Too Much Information!

Some people would like to manage their own health care without having to depend on a doctor. They consult Google, diagnose themselves, and treat themselves. The Do-It-Yourself trend in lab tests continues apace. Without a doctor’s order, patients can get legitimate and/or questionable lab tests directly from various companies such as Any Lab Test Now and Doctor’s Data (which has sued Stephen Barrett for exposing their fraudulent “urine toxic metals” test on Quackwatch). Now a new company, Talking20, has jumped on the self-testing bandwagon with an innovative product that allows people to prick their finger, put a drop of blood on a card, and mail it in from anywhere in the world. Multiple tests are done on a single drop of blood. Results will be available online within a week or even sooner.
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Posted in: Computers & Internet, Diagnostic tests & procedures, Science and the Media

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Once more into the screening breach: The New York Times did not kill your patient

One of the more depressing things about getting much more interested in the debate over how we should screen for common cancers, particularly breast and prostate cancer, is my increasing realization of just how little physicians themselves understand about the complexities involved in weighing the value of such tests. It’s become increasingly apparent to me that most physicians believe that early detection is always good and that it always saves lives, having little or no conception of lead time or length bias. Sadly, just last week, I saw another example of just this phenomenon in the form of an article written by Dr. George Lombardi entitled My Patient, Killed By The New York Times. The depth of Dr. Lombardi’s misunderstanding of screening tests permeates the entire article, which begins with his recounting a story about a patient of his, whose death he blames on The New York Times. After describing the funeral of this 73-year-old man who died of prostate cancer, Dr. Lombardi then makes an accusation:

This one filled me with a special discomfort as I knew a secret: He didn’t have to die. I knew it and he had known it. Had he told?

About 5 years ago he had just retired and had a lot more time on his hands. He was a careful man, lived alone, considered himself well informed. He got into the habit of clipping articles on medical issues and either mailing them to me or bringing them in. They came from a variety of sources and were on a variety of topics. He wasn’t trying to show me up. He was genuinely curious. I kidded him that maybe he’d like to go to medical school in his retirement. ‘No’ he laughed, ‘I just like to be in the know.’

When he came in for his physical in 2008 he told me he’d agree to the DRE but not the PSA (his medical sophistication extended to the use of acronyms: DRE stands for digital rectal exam where I feel the prostate with my gloved finger for any abnormality and PSA for prostatic [sic] specific antigen which is a blood protein unique to the prostate and often elevated in prostate cancer). He had read that the use of PSA as a screening test was controversial. This was the year that the United States Preventive Services Task Force, a government panel that issues screening guidelines, recommended against routine PSA screens for older men. It was often a false positive (the PSA was elevated but there was no cancer), led to unnecessary biopsies, and besides most prostate cancers at his age were indolent and didn’t need to be treated. I countered that prostate cancer was the second leading cause of cancer deaths in men and that it was better to know than not to know. This way it would be our decision. The patient with his doctor deciding what was best. But no, he wanted to stick to his guns and since the DRE was normal no PSA blood test was sent.

After describing a conversation with the man’s daughter, who said, “My father was killed by The New York Times,” Dr. Lombardi then goes on to anecdotal evidence and a cherry-picked publication to support his view, quoting an oncologist who says he’s “seeing more men presenting with advanced prostate cancer” and then referring to a single paper in the current Annals of Internal Medicine about PSA screening. Before I look at the article and a recently published paper on screening mammography that made the news, I can’t help but point out that I (mostly) agree with Dr. Lombardi when he says:

Public health doctors, policy experts and journalists tend to look at the population as a whole. It is a better story if it is one story. It makes a better headline. Their statistics are people I sit across from everyday trying to figure out what the future holds. We each have our job to do.

The problem is, of course, that Dr. Lombardi takes that observation and draws the wrong conclusion, namely that his patient died because of lack of screening. He attacks a straw man, sidestepping the true argument, namely that evidence shows that PSA screening probably causes more harm than good for men at average risk of prostate cancer. Unfortunately, Dr. Lombardi obviously does not understand some very basic concepts behind cancer screening, nor does he apparently recognize that doctors who deal with the population-level data that we have regarding screening tests and try to apply them to individual patients are actually looking in a very systematic way about what the benefits of screening are to the individual patient. More on that later. In the meantime, although I wouldn’t go quite as far as Dr. John Schumann did in criticizing Dr. Lombardi, I do view his lament as a jumping off point to look at some recent data on screening for the two most common cancers, breast and prostate.

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Posted in: Cancer, Diagnostic tests & procedures, Politics and Regulation, Public Health, Science and the Media

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Nutrigenomics – Not Ready for Prime Time

Quackery in medicine takes many forms – use of bad science (pseudoscience), fraud, and reliance on mysticism are a few examples. Perhaps the most insidious form of dubious practice, however, is to use genuine and promising medical science to promote treatments that are simply not at the point of clinical application. New treatments, and especially new approaches to treatment, in medicine often take years or decades of research before we get to the point that we have sufficient clinical evidence of safety and effectiveness to apply the treatment in clinical practice.

One example of the premature promotion of an otherwise legitimate scientific medical treatment are the many dubious stem cell clinics promising cures for serious diseases. Stem cell science is real, but we are still in the long period of build up when we are mostly doing basic and animal research. Human clinical trials are just beginning.

Another treatment approach that is being prematurely promoted by some is nutrigenomics. The claim is that by analyzing one’s genes a personalized regimen of specific nutrients can be developed to help their genes function at optimal efficiency. One website that promises, “Genetics Based Integrative Medicine” contains this statement:

Nutrigenomics seeks to unravel these medical mysteries by providing personalized genetics-based treatment. Even so, it will take decades to confirm what we already understand; that replacing specific nutrients and/or chemicals in existing pathways allows more efficient gene expression, particularly with genetic vulnerabilities and mutations.

The money-quote is the phrase, “it will take decades to confirm what we already understand.” This is the essence of pseudoscience – using science to confirm what one already “knows.” This has it backwards, of course. Science is not used to “confirm” but to determine if a hypothesis is true or not.

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Posted in: Diagnostic tests & procedures, Nutrition

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A holiday round in the mammography debate

There are times when the best-laid blogging plans of mice and men often go awry, and this isn’t always a bad thing. As the day on which so many Americans indulge in mass consumption of tryptophan-laden meat in order to give thanks approached, I had tentatively planned on doing an update on Stanislaw Burzynski, given that he appears to have slithered away from justice yet again. Then what to my wondering eyes should appear in my e-mail in box but news of a study that practically grabbed me by my collars, shook me, and demanded that I blog about it. As if to emphasize the point, suddenly e-mails started appearing by people who had seen stories about the study and, for reasons that I still can’t figure out after all these years, were interested on my take on the study. Yes, I realize that I’m a breast cancer surgeon and therefore considered an expert on the topic of the study, mammography. I also realize that I’ve written about it a few times before. Even so, it never ceases to amaze me, even after all these years, that anyone gives a rodential posterior about what I think. Then I started getting a couple of e-mails from people at work, and I knew that Burzynski had to wait or that he would be relegated to my not-so-secret other blog (I haven’t decided yet).

As is my usual habit, I’ll set the study up by citing how it’s being spun in the press. My local home town paper seems as good a place to begin as any, even though the story was reprinted from USA Today. The title of its coverage was Many women receiving unnecessary breast cancer treatment, study shows, with the article released the day before the study came out in the New England Journal of Medicine:
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Posted in: Cancer, Diagnostic tests & procedures, Public Health

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Clinical Practice Guidelines: Cholesterol Tests for Children?

The American Academy of Family Physicians journal American Family Physician (AFP) has a feature called Journal Club that I’ve mentioned before.  Three physicians examine a published article, critique it, discuss whether to believe it or not, and put it into perspective. In the September 15 issue  the journal club analyzed an article that critiqued the process for developing clinical practice guidelines. It discussed how two reputable organizations, the United States Preventive Services Task Force (USPSTF) and the American Academy of Pediatrics (AAP) looked at the same evidence on lipid screening in children and came to completely different conclusions and recommendations.

The AAP recommends testing children ages 2-10 for hyperlipidemia if they have risk factors for cardiovascular disease or a positive family history. The USPSTF determined that there was insufficient evidence to recommend routine screening. How can a doctor decide which recommendation to follow? (more…)

Posted in: Diagnostic tests & procedures, Science and Medicine

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Mouse “avatars”: New predictors of response to chemotherapy?

Over the years, I’ve written a lot about “personalized medicine, mainly in the context of how the breakthroughs in genomic medicine and data pouring in from the Cancer Genome Atlas is providing the raw information necessary for developing truly personalized cancer therapy. The problem, of course, is analyzing it and figuring out how to apply it. Another problem, of course, is developing the necessary targeted drugs to attack the pathways that are identified as being dysregulated in cancer cells. Oh, and there’s that pesky evolution of resistance to antitumor therapies. Indeed, most recently, the Cancer Genome Atlas is bearing fruit in breast cancer (a study that I’ve been meaning to blog about).

One problem with modeling the pathways based on next generation sequencing data and expression profiling is testing whether therapies predicted to work from these analyses actually do work without actually testing potentially toxic drugs on patients. Cell culture is notoriously unreliable as a predictor. However, there is another way that’s intriguing. Unfortunately, as intriguing as it is, it has numerous problems, and, unfortunately, it’s being prematurely marketed to patients. Although I had heard of this technique as a research tool before, I learned about its marketing to patients when I came across an article by Andrew Pollack in the New York Times entitled Seeking Cures, Patients Enlist Mice Stand-Ins. Basically, it’s about a trend in science and among patients to use custom, “personalized’ mouse xenograft models in order to do “personalized” therapy:
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Posted in: Basic Science, Cancer, Clinical Trials, Diagnostic tests & procedures

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The mammography wars heat up again (2012 edition)

One issue that keeps coming up time and time again for me is the issue of screening for cancer. Because I’m primarily a breast cancer surgeon in my clinical life, that means mammography, although many of the same issues come up time and time again in discussions of using prostate-specific antigen (PSA) screening for prostate cancer. Over time, my position regarding how to screen and when to screen has vacillated—er, um, evolved, yeah, that’s it—in response to new evidence, although the core, including my conclusion that women should definitely be screened beginning at age 50 and that it’s probably also a good idea to begin at age 40 but less frequently during that decade, has never changed. What does change is how strongly I feel about screening before 50.

My changes in emphasis and conclusions regarding screening mammography derive from my reading of the latest scientific and clinical evidence, but it’s more than just evidence that is in play here. Mammography, perhaps more than screening for any disease, is affected by more than just science. Policies regarding mammographic screening are also based on value judgments, politics, and awareness and advocacy campaigns going back decades. To some extent, this is true of many common diseases (i.e., that whether and how to screen for them are about more than just science), but in breast cancer arguably these issues are more intense. Add to that the seemingly eternal conflict between science and medicine communication, in which a simple message, repeated over and over, is required to get through, versus the messy science that tells us that the benefits of mammography are confounded by issues such as lead time and length bias that make it difficult indeed to tell if mammography—or any screening test for cancer, for that matter—saves lives and, if it does, how many. Part of the problem is that mammography tends to detect preferentially the very tumors that are less likely to be deadly, and it’s not surprising that periodically what I like to call the “mammography wars” heat up. This is not a new issue, but rather a controversy that flares up periodically. Usually this is a good thing.

And these wars just just heated up a little bit again late last week.
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Posted in: Cancer, Diagnostic tests & procedures, Politics and Regulation, Public Health

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Cancer care in the U.S. versus Europe: Is more necessarily better?

The U.S. is widely known to have the highest health care expenditures per capita in the world, and not just by a little, but by a lot. I’m not going to go into the reasons for this so much, other than to point out that how to rein in these costs has long been a flashpoint for debate. Indeed, most of the resistance to the Patient Protection and Affordable Care Act (PPACA), otherwise known in popular parlance as “Obamacare,” has been fueled by two things: (1) resistance to the mandate that everyone has to buy health insurance, and (2) the parts of the law designed to control the rise in health care costs. This later aspect of the PPACA has inspired cries of “Rationing!” and “Death panels!” Whenever science-based recommendations are made that suggest ways to decrease costs by reevaluating screening tests or decreasing various tests and interventions in situations where their use is not supported by scientific and clinical evidence, whether by the government or professional societies, you can count on it not being long before these cries go up, often from doctors themselves.

My perspective on this issue is that we already “ration” care. It’s just that government-controlled single payer plans and hybrid private-public universal health care plans use different criteria to ration care than our current system does. In the case of government-run health care systems, what will and will not be reimbursed is generally chosen based on evidence, politics, and cost, while in a system like the U.S. system what will and will not be reimbursed tends to be decided by insurance companies based on evidence leavened heavily with business considerations that involve appealing to the largest number of employers (who, let’s face it, are the primary customers of health insurance companies, not individuals insured by their health insurance plans). So what the debate is really about is, when boiled down to its essence, how to ration care and by how much, not whether care will be rationed. Ideally, how funding allocations are decided would be based on the best scientific evidence in a transparent fashion.

The study I’m about to discuss is anything but the best scientific evidence.
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Posted in: Cancer, Diagnostic tests & procedures, Politics and Regulation, Science and the Media

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