Do we all need PSA tests?

Say your doctor offers to run a PSA test, which might detect early signs of prostate cancer.  The test is free to you, because insurance covers it.  And you're already getting a blood test to measure cholesterol, so the cancer test doesn't involve any extra pain.  Why not?  And by the way, the American Urological Association recommends regular PSA screening for all men over 40.  Based on this information (or less), millions of men get a PSA test every year.

But hold on.  Suppose your doctor tells you a different story.  First he explains that a recent, large-scale US study looked at the effect of annual PSA screening on more than 75,000 men, and found no benefit at all.  A separate large study in Europe showed a very small benefit, but only in 2 of the 7 countries participating in the study.  Suppose your doctor also explained that if you have a positive PSA test, there's an 80% chance that it will be false - that you won't have cancer.

Suppose your doctor also explained that "PSA-based screening leads to a substantial overdiagnosis of prostate tumors" and that treatment usually requires surgery.  The effects of treatment are serious: 20-30% of men treated with surgery and radiation suffer from long-term incontinence and erectile dysfunction.

Prostate cancer tends to grow so slowly that many men with prostate cancer should not be treated at all.  Unfortunately, once someone knows he has cancer, there's a very good chance he will elect treatment, even though we can't really tell if treatment will help.

Do you still want a PSA test?  Do you want one every year?

Well, after a thorough review of the evidence from multiple trials, the US Preventive Services Task Force recommended a few weeks ago that men not get PSA screening for prostate cancer.  They concluded:

"there is moderate certainty that the benefits of PSA-based screening for prostate cancer do not outweigh the harms." (USPSTF, Annals of Internal Medicine, 22 May 2012)

This recommendation, although based on a thorough assessment of risks and benefits, was met with howls of protest from urologists, who conduct most of the prostate cancer screening and treatment in the U.S. and elsewhere.  The American Urological Association stated bluntly:

"The AUA is outraged and believes that the Task Force is doing men a great disservice by disparaging what is now the only widely available test for prostate cancer, a potentially devastating disease."

The AUA also issued press releases and launched a lobbying effort, asking their members to contact the media and Congress.  They even provided a sample letter for urologists to send to their representatives in Congress.

Unfortunately for the AUA, their responses contain a very slanted presentation of the facts.  The AUA president's response emphasizes the studies that found a benefit for PSA testing, but ignores those that found no benefit.  In addition to this cherry-picking, they make the misleading claim that the recent U.S. PLCO study found "a significant reduction of prostate cancer death rates," which it did not.  In fact, the PLCO study found a higher death rate from prostate cancer in men who received PSA testing.
And the AUA statements ignore the very serious risks of prostate surgery; essentially they are pretending the risk is zero.

Why did the urologists react so strongly?  The answer appears to be simple: money.  Urologists make a lot of money on prostate cancer treatments. The USPSTF estimated that in the first 20 years of PSA testing, 1 million additional men were treated as a result of screening.   And if the surgery is unnecessary, you don't get a refund.  

So who are you going to believe?  The Preventive Task Force report presents a thorough review, laying all the details on the table.  Their members don't make a profit from prostate surgeries.  Their report simply more credible than the knee-jerk reaction from the urologists' association.  I'll let the Task Force have the last word:

"The harms of PSA-based screening for prostate cancer include a high rate of false-positive results and accompanying negative psychological effects, high rate of complications associated with diagnostic biopsy, and—most important—a risk for overdiagnosis coupled with overtreatment. Depending on the method used, treatments for prostate cancer carry the risk for death, cardiovascular events, urinary incontinence, erectile dysfunction, and bowel dysfunction. Many of these harms are common and persistent." 

At my last checkup, my doctor asked if I wanted a PSA test.  I told him no thanks.

Government subsidies for chiropractic education

Source: daryl-cunningham.blogspot.com

The U.S. is having a political debate about college tuition loans.  Everyone seems to be in favor of keeping the loan rates low, but politicians disagree about how to pay for the subsidized rates.  (The interest rate on government-guaranteed loans will double this July, from 3.4% to 6.8%, unless Congress takes action.)

Lost in this fight is any discussion at all about which students - and which colleges - get these subsidies.  Right now, the subsidized loans are available to almost any institution that calls itself a college or university.

But what about institutions that provide a substandard education?  Or worse, what about institutions that educate people in quackery and pseudoscience?  Subsidies to these institutions are worse than useless.  These so-called colleges spread misinformation that will require much more investment to correct, if it is even possible.  Why, to be specific, is the U.S. government subsidizing students to attend chiropractic colleges?

Chiropractic colleges are a relatively new invention, as is the entire profession.  Chiropractic was invented out of whole cloth by D.D. Palmer in the 1890s.  He mistakenly believed that misalignments of the spine, which he called subluxations, caused a vast range of health problems, even infectious diseases.  Over a century later, chiropractic colleges continue to preach this nonsense; here is what Palmer College of Chiropractic says:

"Improper function of the spine due to slight misalignments—called subluxations—can cause poor health or function, even in areas far removed from the spine and spinal cord itself."

Subluxations have never been shown to cause disease. In fact, subluxations of the spine have not even been shown to exist.  Despite the thorough lack of evidence, chiropractors appear to be quite skilled at keeping patients returning for "adjustments" to maintain good health.  I wonder how much time is spent in chiropractic colleges teaching students about the need for regular spinal adjustments? As retired chiropractor Sam Homola wrote recently:

"The only thing unique about chiropractic is its basic definition as a method of adjusting vertebral subluxations to restore and maintain health....  The subluxation theory has been the chiropractic profession’s only reason for existence since its inception in 1895."

I wonder, too, if chiropractic colleges educate their students about the risk of stroke from their treatments. The rapid head-twisting move that many chiropractors use, which produces a startling cracking sound in the neck, also carries a small but real (and frightening) risk of tearing one of the arteries in the neck.  Chiropractors dispute this claim, but studies have shown that patients with vertebral tears are much more likely to have recently visited a chiropractor.  A systematic review of the evidence in 2010 concluded

"Numerous deaths have occurred after chiropractic manipulations. The risks of this treatment by far outweigh its benefit."

On top of their dubious educational programs, chiropractic colleges pay their presidents astonishingly high salaries, as documented recently in the Chronicle of Higher Education, which pointed out that

"the presidents of chiro­practic colleges are taking in some of the biggest paychecks in higher education." 

For example, the president of Logan College of Chiropractic, which has a budget of $24.5 million, earned $791,418 in 2009.  That's the same salary earned by the president of CalTech, which has a budget 100 times larger.

Low-cost student loans provide a benefit to many students and their universities.  But we don't need to subsidize erroneous and misguided colleges that teach their students nonsense.  If Congress is going to extend the student loan program, they should take this chance to make the program far more selective.  Helping students get a good education helps the country.  Lending students money to learn pseudoscience does just the opposite.

Nobel laureate joins the autism cranks at AutismOne conference

If you're reading this from anywhere but Chicago, you just missed the Autism One conference, which ends today.  This conference, run by Jenny McCarthy and Generation Rescue, purports to tell parents "the truth" about autism.

The conference is a veritable festival of unproven claims, offering a powerful but false message of hope to parents who are desperately searching for new treatments for their children.  It's also a nexus for anti-vaccinationists, who run special seminars educating parents about how to get vaccine exemptions so that they can enroll their unvaccinated children in public schools.

A look at the presentations reveals that rather than presenting "the truth," one speaker after another is making unsupported, unscientific claims and then offering their own special therapy.  The one thing that most of these presentations have in common is that the speaker is making money from selling their so-called treatments.  For example, Anat Baniel offers her self-named "Anat Baniel method" and is promoting it through ads in the conference program.  Other speakers are offering special diets, hyperbaric oxygen therapy, and in perhaps the most damaging treatment, Mark and David Geier's chemical castration therapy.  Mark Blaxill is there, still pushing the thoroughly disproven link between mercury and autism, and hawking his book on the topic.

The other major theme of the conference is conspiracies: how the government, big pharma, and the scientific establishment are all conspiring to hide "the truth" about autism, which the speaker will reveal to the audience. Coincidentally, many of the speakers also offer treatments, for a fee.

This year's speakers include Jenny McCarthy and Andrew Wakefield, as usual, but also a new entry: Luc Montagnier.

Jenny McCarthy has been a leader of the anti-vaccine movement for over a decade.  She's a former Playboy playmate and MTV host, with no medical qualifications whatsoever, who is convinced that vaccines caused her son's autism.  She's been spreading her anti-vaccine message very effectively, with particular help from Oprah Winfrey and Larry King, who gave her prime television exposure countless times.  Oprah even offered McCarthy her own show, until McCarthy ditched Oprah for NBC.

Andrew Wakefield, the thoroughly discredited doctor who falsified data in order to push his false hypothesis that autism is caused by the MMR vaccine - whose medical license was revoked in the UK, and whose famous 1998 paper on autism and vaccines was retracted after it was shown to be fraudulent - claims that his talk "offers solutions [that] will be ignored by those in power and the more dire of its predictions will result."  Too bad I missed that one.

It's no surprise that Jenny McCarthy and Andrew Wakefield, leaders of the anti-vaccine movement, are speaking at AutismOne.  Much more surprising is the presence of Nobel laureate Luc Montagnier, co-discoverer of the link between the HIV virus and AIDS.  What is he doing at this festival of pseudoscience?

Well, apparently Montagnier has gone off the deep end into pseudoscience himself.  He claims that his new group, Chronimed, has discovered in autistic children

"DNA sequences that emit, in certain conditions, electromagnetic waves.  The analysis by molecular biology techniques allows us to identify these electromagnetic waves as coming from … bacterial species."

What the heck?  In what seems to be a desperate effort to stay relevant, Montagnier is promoting wild theories with little scientific basis, and now he is taking advantage of vulnerable parents (see his appeal here) to push a therapy of long-term antibiotic treatment for autistic children.

This is truly a wacky theory.  Montagnier hasn't been able to publish this in a proper journal, for a very good reason: it's nonsense.   He claims that quantum field theory - an area of physics in which he has no qualifications - explains how electromagnetic waves emanating from DNA can explain not only autism, but also Alzheimer's disease, Parkinson's disease, multiple sclerosis, Lyme disease, and rheumatoid arthritis.  Montagnier makes these claims and more in a self-published paper that he posted on arXiv.

This isn't Montagnier's first crazy idea: just a year ago, he claimed that DNA molecules can teleport between test tubes, also based on some kind of quantum hocus pocus.  This crackpot claim should have been ignored, and it would have been, if not for the fact that Montagnier is a Nobel laureate.  He's also endorsed homeopathy, another quack treatment.

This is a sad coda to a brilliant medical career.  Not only is Montagnier espousing junk science and tarnishing his own reputation, but he is lending credibility to the AutismOne conference, which is a festival of hucksters and snake-oil salesman, offering unproven, ineffective, and even harmful treatments to vulnerable children and their parents.

Autism is a complex, difficult disease.  Thousands of researchers are pouring their hearts and souls into understanding the disease and developing new treatments.  AutismOne does a terrible disservice to autistic children by siphoning away time, energy, and money that could instead go into real science.  We can only hope that it will fade away.

1098 reasons why women are genetically superior to men

Calico cats prefer Mother's Day

Everyone knows that women have two X chromosomes, while men have just one.  Instead of a second X, men have a Y chromosome. The X chromosome is far larger than Y, with 1098 genes  versus just 27 genes that are unique to the Y chromosome.

Well, one might argue, men have all the X chromosome genes too, so what's the advantage to having an extra copy?  It seems that we only need one copy of each of these 1098 X genes.

As it turns out, female mammals (not just humans) have a unique advantage over males: they get to choose, for each copy of those 1098 genes, which ones to use.  And they can pick and choose different ones along the X chromosome, sometimes using the gene (called an allele) from their own mother, other times using the allele from their father.  The other copy is turned off, through a remarkable process called X inactivation.

The female advantage is more than just the choice of which X chromosome to use.  An amazing feature of genetics is that females can use different genes in different cells.  The calico cat shown here is a beautiful illustration of this: early in development, some of the pigment cells in this cat chose the orange fur gene, while other cells chose the black fur gene.  As these cells divided, they created patches of black and orange fur.  As far as anyone can tell, these choices are random, which is why every calico cat has a different pattern of black and orange fur.

It's also why every calico cat is female.

So there you have it: women have over 1000 genes that offer a choice, while men are stuck with a single X chromosome.  Quite an advantage.  (Of course, we men can argue that those 27 Y chromosome genes must be pretty special too.)

Oh, and there's one more advantage women have over men: only women can be moms.  Happy Mother's Day!

Zinc still doesn't work very well for colds

Cold cure manufacturers continue to push zinc as a cure, despite the lack of evidence.  Today, the Washington Post reported, not for the first time, that taking zinc will shorten the duration a cold by three days in adults.  Sounds pretty good!  Only it's wrong.

The Post reporter apparently didn't really get past the abstract for the new study, which isn't actually a study at all, but just a review of 17 other studies.  The review appeared on May 8 in the Canadian Medical Association Journal.

ALL of the studies were funded by the companies that make zinc supplements, mostly large pharmaceutical companies.  (Big Pharma or Big Supp, they are often the same companies.)  Here's a partial list of the sponsors: Warner Lambert, McNeil Consumer Products, Weider Nutrition, Truett Laboratories, Bristol Myers, Berko Ilac, and Quigley.  Not that there's anything wrong with that!

One problem with the Washington Post summary is that the benefit wasn't really three days, even if you believe the results.  Although the study looked at 17 trials, the core analysis only used eight of them, all of which used patients with naturally acquired colds.  The average benefit was 1.6 days, not 3 days, and it was highly variable.  Reuters and Fox reported the story more accurately as "one and a half days" and pointed out that the effect was just over two and a half days in adults.

Somehow, though, the benefit disappeared in children.  Could this be because children don't care so much about telling the investigators what they want to hear?

And what about those trials that didn't use naturally occurring colds.  As I pointed out in a recent blog post, if you look at only the studies where the researchers intentionally gave people a cold, the effect vanishes.

"The more rigorously scientific studies, where you took a group of people and gave half of them zinc and half a placebo and inoculated their nose with a cold virus, found there were no differences," said Terence Davidson, director of the UC San Diego Nasal Dysfunction Clinic in a February interview.

None of this stops ProPhase (NasdaqGM: PRPH), maker of ColdEeze zinc products, from making this claim on their website:

"Cold-EEZE® has been clinically proven to shorten the duration of the common cold by nearly half."  

As evidence, their website points to three studies from 10-20 years ago.  They conveniently ignore the more recent studies that showed far less (possibly no) benefit.

The authors of the latest review article graded the quality of evidence for five different outcomes.  Their report card on these studies has one "Moderate" and four "Low" grades.  Moderate means "further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.  Most of the grades were "low," which means

"further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate."  

So the authors themselves don't really trust their own study!  In the end, they conclude that "there is only a weak rationale" to recommend zinc.  And previous studies, not funded by supplement manufacturers, showed no benefit.  Who are you going to believe?

Save your money and use it to buy chicken soup instead.*

*The author receives no financial backing from the makers of chicken soup, although he does like it and would appreciate a free sample.

Falling 300 feet and living to tell about it

How far can a human being fall and survive?  Normally, not very far.  People usually survive falls from a height of 20-25 feet (6-8 meters), but above that, things get very deadly very fast.  A study done in Paris in 2005 looked at 287 victims of falls, and found that falls from 8 stories (30 meters) or higher were 100% fatal.

How about 300 feet? Last fall, a remarkable case report appeared in an little-noticed journal, the Scandinavian Journal of Trauma, Resuscitation, and Emergency Medicine. The article begins with this astonishing sentence:

"We report the case of a 28-year old rock climber who survived an 'unsurvivable' injury consisting of a vertical free fall from 300 feet onto a solid rock surface."

This is no ordinary case report.  The accident happened when a 28-year-old woman and her boyfriend, both experienced rock climbers, were climbing in the Rocky Mountains in Colorado.  Both were wearing helmets.  The woman took the lead on the final pitch of a 300-foot (90-meter) climb.  At the very top, after securing the rope, her climbing harness failed.  She fell 200 feet straight down, hit a flat rock surface, then fell another 100 feet.  Her boyfriend climbed down as rapidly as he could, and found her at the bottom, alive.  This appears to be the highest vertical free fall onto a hard surface that a human has been documented to survive.

The list of the climber's injuries, described in detail in the article, is frighteningly long.  The article shows a picture of her, awake and off the respirator, on her 4th day in the hospital.  (The patient agreed to have her case published along with her photo.)  Despite her extensive injuries, including paralysis of both legs, she otherwise recovered remarkably well and "was transferred to her local community regional spinal cord rehabilitation center out-of-state at 2½ months after injury in excellent conditions."

The authors of the article focused on this question: if you fall a very, very long distance, how should you land?  The authors of the study concluded that a critical factor in the climber's survival was that she landed feet first.  As they wrote: " a fall on both feet represents the 'ideal' body to impact surface position with regard to survival from vertical falls."  Landing feet first allows the lower body to absorb most of the deceleration force, as they illustrated in the figure reproduced here.

This case reminds me of a famous paper from BMJ back in 2003: "Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials."  In that paper, G.C.S. Smith and J.P. Pell complained that no one has ever done a properly controlled experiment to determine if parachutes really work.

"We were unable to identify any randomised controlled trials of parachute intervention," they wrote.

They argued that "an adverse outcome after free fall is by no means inevitable," a point that the current study would seem to support.  However, I can't agree with Smith and Pell's conclusion: "We think that everyone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute."

University of Florida eliminates Computer Science Department. At least they still have football.

Wow, no one saw this coming.  The University of Florida announced this past week that it was dropping its computer science department, which will allow it to save about $1.7 $1.4 million.  The school is eliminating all funding for teaching assistants in computer science, cutting the graduate and research programs entirely, and moving the tattered remnants into other departments.

Let's get this straight: in the midst of a technology revolution, with a shortage of engineers and computer scientists, UF decides to cut computer science completely?

Students at UF have already organized protests, and have created a website dedicated to saving the CS department.  Several distinguished computer scientists have written to the president of UF to express their concerns, in very blunt terms.  Prof. Zvi Galil, Dean of Computing at Georgia Tech, is "amazed, shocked, and angered."  Prof. S.N. Maheshwari, former Dean of Engineering at IIT Delhi, calls this move "outrageously wrong."  Computer scientist Carl de Boor, a member of the National Academy of Sciences and winner of the 2003 National Medal of Science, asked the UF president "What were you thinking?"

(Note to the students, if you need more quotes for your site: I think this move is shockingly short-sighted.  The University of Florida is moving backwards while the rest of the world moves ahead.)

Meanwhile, the athletic budget for the current year is $99 $97.7 million, an increase of more than $2 million from last year.  The increase alone would more than offset the savings supposedly gained by cutting computer science.

Now, I'm not saying that UF has chosen football over science. Actually, the real villains here are the Florida state legislators, who have cut the budget for their flagship university by 30% over the past 6 years.

Meanwhile, just two days ago, Florida governor Rick Scott approved the creation of a brand-new public university, Florida Polytechnic University, to be located near the city of Tampa.  In an unintentionally ironic statement, Gov. Scott said

"At a time when the number of graduates of Florida's universities in the STEM [science, technology, engineering, and mathematics] fields is not projected to meet workforce needs, the establishment of Florida Polytechnic University will help us move the needle in the right direction."

Heads up, Gov. Scott: no one is going to believe that you're supporting technical education when your flagship university is eliminating its Computer Science Department. Since cutting support for universities seems to be a major agenda item for you and the legislature, why stop at 30%?  With just a bit more cutting, you could get rid of those annoying universities entirely.  Let the rest of the country worry about higher education! Florida can focus on orange groves and golf courses. Oh, and football.

[Update 25 April 8:30pm: After my Forbes blog post on this topic went viral, UF President Bernie Machen announced that they are dropping their plan to eliminate Computer Science.  See my followup post here for details and a link.]