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Early detection of cancer, part 2: Breast cancer and MRI

Note: If you haven’t already, you should read PART 1 of this two-part series. It defines several terms that I will be using in this post, and I don’t plan on explaining them again, given that they were explained in detail in Part 1. Of course, if you’re a medical professional and already know what lead time bias, length bias, and stage migration are, then it goes without saying that you should still read Part 1 for its scintillating prose.

ResearchBlogging.orgWhen last I left this topic three weeks ago, I had discussed why detecting cancer at ever-earlier stages and ever-smaller sizes is not necessarily an unalloyed good. At that time, I discussed in detail a landmark commentary in the New England Journal of Medicine entitled, Advances in Diagnostic Imaging and Overestimations of Disease Prevalence and the Benefits of Therapy. The article, although nearly 15 years old, rings just as true today in its cautioning doctors about whether ever-increasing diagnostic sensitivity that imaging technology and new blood tests were (and are) providing was actually helping patients as much as we thought it was. Before we dive into this problem as applied to breast cancer, let’s review what Drs. Black and Welch had to say about screening tests for breast cancer 15 years ago, as way of background and linking my last post and this one:

Before the widespread use of mammography, most breast cancers were discovered on physical examination, as palpable lumps. In one of the few studies to assess directly the accuracy of physical examination in screening for breast cancer, only 27 percent of tumors more than 1.0 cm in diameter and 10 percent of those less than 1.0 cm in diameter were detected by physical examination. However, the mean size of breast cancers detected by state-of-the-art screening mammography is about 1.0 cm, and many of the cancers detected as microcalcifications are only a few millimeters in size.

Again, prevalence depends on the degree of scrutiny. According to the Connecticut Tumor Registry, clinically apparent breast cancer afflicts about 1 percent of all women between the ages of 40 and 50 years. In a recent medicolegal autopsy study, however, small foci of breast cancer were found in 39 percent of women in this age group. Most cancers were in the form of ductal carcinoma in situ. Furthermore, over 45 percent of the women with cancer had two or more lesions, and over 40 percent had bilateral lesions. Although it has been argued that such small in situ lesions are not detected by and are therefore irrelevant to screening mammography, about half the lesions in that study were detected, usually as microcalcifications, on postmortem plain-film radiography of the resected breasts. Because of continual technical improvements and increasingly broad criteria for the interpretation of mammograms, the detection threshold for breast cancer has fallen considerably since the time of the Breast Cancer Screening Project of the Health Insurance Plan of Greater New York (1963 to 1975). This can explain the increased prevalence of cancer on mammographic screening, from 2.717 to 7.614 per 1000 examinations (with the incidence increasing from 1.517 to 3.214 per 1000 examinations). The lower detection threshold can also explain the increase in the percentage of carcinomas in situ (stage 0) among all mammographically detected cancers — from 12.7 percent to over 30 percent. The principal indication for biopsy has changed from suspicious mass to suspicious microcalcifications. This can explain why the reported incidence of breast cancer has increased and why most of the increase is in smaller lesions, particularly ductal carcinoma in situ.

About a year ago, three major articles hit the medical press that made me start thinking about this more than I had in the past. It’s my job, after all, because breast cancer surgery is a large part of my practice, and I do breast cancer lab-based research. What also tweaked me not to put off doing part 2 of this series is that, just two days ago, there was an abstract presented at the American Society of Clinical Oncology Meeting (where I still am today) that also serves to highlight just how difficult this question of integrating a test as sensitive as MRI into a screening regimen for and preoperative evaluation of breast cancer is and how MRI should fit into in this regimen can be.
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Posted in: Clinical Trials, Public Health, Science and Medicine, Science and the Media, Surgical Procedures

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A real “Era III Emergency Room”

Due to the holiday, I have not had time to compose the usual lengthy and analytic post that readers have come to know and (hopefully) love. However, Dr. Atwood’s Weekly Waluation of the Weasel Words of Woo #6 so perfectly brought a famous (or infamous) parody back from the depths of my memory that I had to go straight to YouTube and find it. I think our readers will appreciate if they haven’t seen it before. The quote that inspired me to resurrect this gem is:

This new era is composed of a blend of the best of what we know of physical, material-based medicine (”Era I”), mind-body medicine (”Era II”), and the caring, compassion, and consciousness that characterize “Era III.” A compelling example is given in the use of all three levels of caring in the “Era III Emergency Room.”He vividly shows us a new kind of emergency department in which an auto crash patient is not only stabilized and sutured but has the suggestion of relaxation imagery along with the lidocaine and nylon. Meanwhile, caring healers take a moment to pray and visualize a positive outcome based on the scientific evidence of the effects of nonlocal mind, employing a network of nonlocal healers as they work.

No, this is the real “Era III Emergency Room”:

The sad thing is, I fear that the above video is not too great an exaggeration of the way medicine is going.I will return next Monday (possibly even sooner) with new material.

Posted in: Humor, Science and Medicine

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Monkey business in autism research

NOTE: I had originally planned on posting Part II of a series on cancer screening. However, something came up on Friday that, in my estimation, requires a timely response. I should also inform readers that, because next Monday is a holiday here in the U.S., I haven’t yet decided whether I will be doing a post next week or not. Stay tuned and check back.

I get e-mail.

Sometimes the e-mail is supportive. Other times, as you might imagine, given some of my posts, it is anything but. On Friday afternoon, I happened to notice an e-mail from an “admirer” of mine that said something like this:

You are a complete jack-ass.

- Generation Rescue

Appended to the e-mail was a link to this article on the Age of Autism blog.

Generation Rescue, as you may recall, is an organization that promotes the idea that vaccines cause autism, and this e-mail almost certainly came from the founder and head of GR, a man named J.B. Handley. In case you don’t know who he is, Handley is a man who is, even by the standards of antivaccinationists, incredibly boorish and possessed of a bull-in-a-china shop manner that alienates even some potentially sympathetic people, although parents who believe that vaccines cause autism seem to love him. He is also quite–shall we say?–flexible in his notions of how vaccines cause autism. Until about a year ago, the Generation website stated unequivocally:

Generation Rescue believes that childhood neurological disorders such as autism, Asperger’s, ADHD/ADD, speech delay, sensory integration disorder, and many other developmental delays are all misdiagnoses for mercury poisoning.

About a year ago, it changed to:

We believe these neurological disorders (“NDs”) are environmental illnesses caused by an overload of heavy metals, live viruses, and bacteria. Proper treatment of our children, known as “biomedical intervention”, is leading to recovery for thousands.

The cause of this epidemic of NDs is extremely controversial. We believe the primary causes include the tripling of vaccines given to children in the last 15 years (mercury, aluminum and live viruses); maternal toxic load and prenatal vaccines; heavy metals like mercury in our air, water, and food; and the overuse of antibiotics.

The kind interpretation is that GR was changing its hypothesis given that the data being published consistently and strongly refuted the myth that mercury in vaccines somehow cause autism. In reality, though, it’s fairly clear that GR was pivoting effortlessly to a hypothesis that not only was nearly completely unfalsifiable but also allowed GR to continue to blame vaccines for autism, which is what it’s really about. More recently, as I have pointed out before, antivaccinationist rhetoric has also pivoted even further and equally as effortlessly to blame unspecified “toxins” or “combinations of toxins” in vaccines. Be that as it may, having felt the love, I have to admit that Mr. Handley sure does know how to charm a guy. When he draws my attention to some abstracts so politely, abstracts that he clearly considers to be very important evidence, how can I refuse to take a look? After all, Mr. Handley himself apparently very much wanted to point me in the direction of these three abstracts, and it would be downright churlish of me to deny him and refuse to look at the studies with as open a mind as possible.
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Posted in: Basic Science, Medical Academia, Neuroscience/Mental Health, Politics and Regulation, Public Health, Vaccines

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The early detection of cancer and improved survival: More complicated than most people think

“Early detection of cancer saves lives.”

How many times have you heard this statement or something resembling it? It’s a common assumption (indeed, a seemingly common sense assumption) that detecting cancer early is always a good thing. Why wouldn’t it always be a good thing, after all? For many cancers, such as breast cancer and colon cancer, there’s little doubt tha early detection at the very least makes the job of treating the cancer easier. Also, the cancer is detected at an earlier stage almost by definition. But does earlier detection save lives? This question, as you might expect, depends upon the tumor, its biology, and the quality and cost of the screening modality used to detect the cancer. Indeed, it turns out that the question of whether early detection saves lives is a much more complicated question to answer than you probably think, a question that even many doctors have trouble with. It’s also a question that can be argued too far in the other direction. In other words, in the same way that boosters of early detection of various cancers may sometimes oversell the benefits of early detection, there is a contingent that takes a somewhat nihilistic view of the value of screening and argues that it doesn’t save lives.

A corrollary of the latter point is that some boosters of so-called “alternative” medicine take the complexity of evaluating the effect of early screening on cancer mortality and the known trend towards diagnosing earlier and earlier stage tumors as saying that our treatments for cancer are mostly worthless and that the only reason we are apparently doing better against cancer is because of early diagnosis of lesions that would never progress. Here is a typical such comment from a frequent commenter whose hyperbolic style will likely be immediately recognizable to regular readers here:

Most cancer goes away, or never progresses, even with NO medical treatment. Most people who get cancer never know it. At least in the past, before early diagnosis they never knew it.

Now many people are diagnosed and treated, and they never get sick or die from cancer. But this would have also been the case if they were never diagnosed or treated.

Maybe early diagnosis and treatment do save the lives of a small percentage of all who are treated. Maybe not. We don’t know.

As is so often the case with such simplistic black and white statements, there is a grain of truth buried under the absolutist statement but it’s buried so deep that it’s well-nigh unrecognizable. Because we see this sort of statement frequently, I thought it would be worthwhile to discuss some of the issues that make the reduction of mortality from cancer so difficult to achieve through screening. I will do this in two parts, although the next part may not necessarily appear next week
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Posted in: Cancer, Public Health, Science and Medicine, Science and the Media

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Mercury emissions from coal-burning power plants and autism: Is there a correlation?

ResearchBlogging.orgOn April 30, outside the courthouse in Dallas, a press conference/rally was held. This particular rally was in response to a new study published by a group led by Dr. Raymond F. Palmer in the Department of Family and Community Medicine at the University of Texas Health Science Center in San Antonio, whose conclusion was that autism prevalence correlates strongly with proximity to mercury-emitting coal-burning power plants and other industrial sources of airborne mercury, the implication being that such sources of mercury may be causal or contributory to the development of autism. Unfortunately, the rally was reported by the media as though this study were slam dunk evidence that mercury environmental mercury is a definite contributor to the development of autism. For example, there is some video (also here) from local news sources of the rally, in the first of which it is stated as fact that mercury caused autism in the child featured in the story and in the second of which a mother who thinks that mercury causes autism is quoted credulously. This study has had much less play in the national news, but antivaccination activists, such as the ones at the Age of Autism website, a site whose main theme is that either mercury in the thimerosal preservative that used to be in childhood vaccines before 2002 or vaccines themselves cause autism, both promoted the rally and posted a glowing and credulous take on the study, as did “alternative medicine” and antivaccinationist website NaturalNews.com.

My first thought upon reading of this is that it is yet more vindication of the science showing that the claim that mercury in thimerosal-containing vaccines is a failed hypothesis. After all, as I have predicted time and time again, as the scientific and epidemiological evidence continued to mount that thimerosal is just plain not associated with autism or autism spectrum disorders, even the most diehard adherents to this belief are starting to realize that they were backing a losing horse, especially since thimerosal was removed from all childhood vaccines other than the flu vaccine in 2001, leaving only trace amounts from the manufacturing process and there is no sign that autism prevalence is falling. That’s why lately, their effort has shifted from primarily demonizing mercury to blaming other “toxins” in vaccines, even to the point that their efforts to demonize some ingredient–any ingredient–in vaccines often reaches ridiculous levels of blatant silliness, such as touting sucrose as one of those “toxins.” Indeed, I was puzzled. If environmental mercury is the new cause of autism, then the rationale antivaccinationists use to demonize vaccines and portray their children as “vaccine-damaged” is much less potent. Why on earth would they tout this study, which, even if a good study (and it’s not), would weaken their arguments against vaccines immeasurably and take power away from their whole new propaganda slogan “Green Our Vaccines”? The only reason I could think of is that perhaps they somehow think that if mercury in the environment can be linked to autism that maybe–just maybe–they can convince people that they were right about mercury in vaccines all along. Indeed, this seems to be the sort of tack that David Kirby took a year ago when he started arguing that mercury emissions from coal-burning power plants in China (which do reach California), coupled with mercury emission from crematoria in which cadavers with mercury fillings were burned, were contributing to the continued increase in the autism caseload in California despite the elimination of thimerosal in 2001.

But what does the study say itself? Is it good evidence that airborne mercury from coal-fueled power plants is an important contributor to the development of autism? I will argue no, because the study’s flaws are so innumerable that it is well nigh uninterpretable. For simplicity’s sake, to summarize its findings, I’ll quote a Science Daily press release about it:
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Posted in: Neuroscience/Mental Health, Public Health, Science and the Media, Vaccines

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The North Carolina Board of Medical Examiners, Dr. Rashid Buttar, and protecting the public from practitioners of non-science-based medicine

One of the most contentious and difficult aspects of trying to improve medical care in this country is enforcing a minimal “standard of care.” Optimally, this standard of care should be based on science- and evidence-based medicine and act swiftly when a practitioner practices medicine that doesn’t meet even a minimal requirement for scientific studies and clinical trials to support it. At the same time, going too far in the other direction risks stifling innovation and the ability to individualize treatments to a patient’s unique situation–or even to use treatments that have only scientific plausibility going for them as a last-ditch effort to help a patient. Also, areas of medicine that are still unsettled and controversial could be especially difficult to adjudicate. Unfortunately, with medicine being regulated at the state level, there are 50 state medical boards, each with different laws governing licensure requirements and standards for disciplining wayward physicians, our current system doesn’t even do a very good job of protecting the public from physicians who practice obvious quackery. The reasons are myriad. Most medical boards are overburdened and underfunded. Consequently, until complaints are made and there is actual evidence of patient harm, they are often slow to act. Also, in my experience, they tend to prefer to go after physicians who misbehave in particularly egregious ways: alcoholic physicians or physicians suffering from other forms of substance abuse; physicians who sexually abuse patients; or physicians who are “prescription mills” for narcotics. These sorts of cases are often much more clear-cut, but most importantly they don’t force boards to make value judgments on the competence and practice of physicians to nearly the extent that prosecuting purveyors of unscientific medicine does.

Dr. Rashid Buttar: Autism and cancer

The reason I’ve been thinking about this issue again is because last Friday it was announced that one of the most dubious of dubious physicians of which I have ever become aware, Dr. Rashid Buttar of North Carolina, was, after many years of practice, finally disciplined by the North Carolina Board of Medical Examiners. Basically, the Board restricted his practice so that he could no longer treat children or cancer patients (more on why those two particular restrictions were imposed below). Once hailed as a hero by antivaccinationists and even once having testified to the Subcommittee on Wellness & Human Rights on autism issues, he is now disgraced.

Dr. Buttar runs a clinic called the Center for Advanced Medicine and Clinical Research, which features on its front page this quote:

“All truth passes through 3 phases: First, it is ridiculed. Second, it is violently opposed, and Third, it is accepted as self-evident.”- Arthur Schopenhauer, 1788-1860.

I can’t resist mentioning that any time I see this particular quote, I know that I’m almost certainly dealing with someone who is far on the fringe, because what one first has to realize about the quote is that non-”truth” never makes it past phase one or two–and rightly so. Right off the bat, we can see that Dr. Buttar has a greatly inflated view of his own importance.
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Posted in: Cancer, Health Fraud, Medical Ethics, Neuroscience/Mental Health, Politics and Regulation, Vaccines

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Barriers to practicing science-based surgery

ResearchBlogging.orgMuch to the relief of regular readers, I will now change topics from those of the last two weeks. Although fun and amusing (except to those who fall for them), continuing with such material for too long risks sending this blog too far in a direction that no one would want. So, instead, this week it’s time to get serious again.

A few weeks ago, I wrote about factors that lead to the premature adoption of surgical technologies and procedures or the “bandwagon” or “fad” effect among surgeons. By “premature,” I am referring to widespread adoption “in the trenches,” so to speak, of a procedure before good quality evidence from science and clinical trials show it to be superior in some way to previously used procedures, either in terms of efficacy, cost, time to recover, or other measurable parameters. As I pointed out before, laparoscopic cholecystectomy definitely fell into that category. The popularity of the procedure spread like wildfire in the early 1990s before there was any good quality data supporting its superiority to the “old-fashioned” gold standard procedure of open cholecystectomy. Another example, although not nearly as dramatic because the number of patients for whom the procedure would be appropriate is much smaller, is transanal endoscopic microsurgery. However, the difficulties in practicing science- and evidence-based medicine don’t just include fads and bandwagon effects. The example of laparoscopic cholecystectomy notwithstanding (which was largely driven by marketing and patient demand), surgical culture is deeply conservative in that it can be very reluctant to change practice even there is very strong evidence saying that they should.
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Posted in: Basic Science, Cancer, Surgical Procedures

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Would you like a liver flush with that colon cleanse?

I have to apologize for last week’s post. I’m not apologizing for the subject matter (the obsession that reigns supreme among some alt-med aficionados over “cleansing” their colons to “purge toxins” and achieve the super-regularity of several bowel movements a day). Rather, I’m sorry I probably didn’t emphasize quite strongly enough just how disgusting one of the links that I included was. Among all the glowing testimonials found there touting how lovers of that “clean feeling” inside felt after having supposedly rid themselves of all that nasty fecal matter caked on the walls of their colons and achieved the Nirvana of many bowel movements a day (or, as one happy customer put it, “awesome adventures in the bathroom” and another put it, “I have not noticed anything really weird come out of me yet, but I am sure that there will be”), there were also links to various pictures people took of their own poop, complete with graphic descriptions. A couple of years ago when I showed an acquaintance of mine the Dr. Natura website shortly after I had discovered it, he declared it the “grossest thing on the web.” Sadly, I had to assure him that it was not–not by a longshot. However, I will try spare you any links to anything significantly grosser, preferring instead to leave finding them as an exercise for interested readers.

After having apologized for perhaps grossing out some of our readers, who come to this site for science- and evidence-based discussions of various so-called “complementary and alternative medicine” therapies, not pictures of the various excretions of the human body proudly lined up by the humans who produced them, I thought about what might be a suitable followup this week to such a topic. There really is only one followup that’s appropriate to this stuff, believe it or not. The problem with which I wrestled is that it really is pretty much as disgusting as last week’s topic, if not more so. (You’ll soon see why.) So there I was, trapped on the horns of a dilemma. Hesitating only momentarily, though, as any good general surgeon would do (remember, before I specialized in breast cancer surgery I was a general surgeon, as prone to dive into big brown on the loose as any other general surgeon), I decided just to dive in to the topic as I would have in the old days dived into a particularly foul belly full of purulence, particularly since this week’s “CAM” modality of choice claims to be able to take away a big chunk of the “bread and butter” practice of general surgery by curing a common surgical disease without all that nasty cutting, even if these days it’s almost always done laparoscopically.

So, are you ready for liver flushes? Of course you are. Don’t you want a way to “remove gallstones without surgery“?

Of course you do.
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Posted in: Cancer, Health Fraud, Science and Medicine

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Colon “cleanses”: A load of you know what…

Death begins in the colon.

Perhaps you’ve heard this little bit of “alternative medicine” wisdom. Oddly enough, I had never heard it until well after I had become a surgeon (although my first thought upon hearing it was that it would make a killer name for a rock band or a blog). That’s when I began encountering claims that seemed to indicate that constipation was the most evil thing in the world, something that must be avoided at all costs. Naturally, I wondered just what the heck was meant by this bit of “wisdom.” What, I wondered, was it based on? What, I wondered, was the purpose of it? To answer this question, recently I decided to go back and review what people say about colon health:

Have you ever considered this simple question: Are you clean inside?

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Posted in: Science and Medicine, Surgical Procedures

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On the ethics of clinical trials of homeopathy in Third World countries

ResearchBlogging.orgI’m on the record multiple times as saying that I reject the entire concept and nomenclature of “alternative medicine” as being distinct from “conventional” medicine as a false dichotomy, when in reality there should be just “medicine.” Indeed, if there is one major theme to which this blog is dedicated it’s that medicine should be as much as possible science-based, a concept that takes into account not just clinical trials, which are prone to all sorts of false-positive results in the case of modalities that have no plausibility from a scientific perspective. In essence, I advocate treating “alternative” medicine the same as “conventional” medicine subjecting it to the same scientific process to determine whether it has efficacy or not, after which medicine that is effective is retained and used and medicine that fails the test is discarded. Where it comes from, the “alternative” or the “conventional” medical realm, matters little to me. All that matters is that it is based on sound science and that it has been demonstrated to have efficacy significantly greater than that of a placebo.

Given that, you’d think I’d be all in favor of subjecting alternative medicine, be it woo or more credible, to rigorous scientific testing. In many cases, you’d be right. My sole caveat is that, when testing alt-med, priority should be given to modalities that have at least a modicum of scientific plausibility, even if a bit tenuous. Herbal remedies would thus be at the front of my line to be tested, while obvious woo whose core principle on which it is based is so utterly ridiculous and scientifically implausible (like homeopathy, for instance) would be relegated to the back of line, if it’s ever tested at all. More implausible modalities that might work (albeit by a method that has nothing to do with the “life energy” manipulation that is claimed for it) like acupuncture would be somewhere in the middle. It’s a matter of resource prioritization, in which it makes little sense to test blatant woo before more plausible therapies are examined. Indeed, it’s arguable whether blatant woo like homeopathy should even have resources wasted testing it at all, given its extreme scientific improbability. Finally, regardless of what modality is being tested in scientific and/or clinical trials, it has to be done according to the highest ethical standards, on adults fully cognizant of or able to be taught about the questions being asked, the issues involved, and the potential risks who are thus able to give truly informed consent.
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Posted in: Homeopathy, Medical Ethics, Public Health, Science and Medicine

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