nos-trum. pronunciation: \nos'-trum\. noun. Etymology: Latin, neuter of noster our, ours.
1. a medicine of secret composition recommended by its preparer but usually without scientific proof of its effectiveness.
2. a usually questionable remedy or scheme.
See here for more discussion.

Wednesday, January 14, 2009

IF SILICONE IS TOXIC, SHOULD I LAY ON THE BEACH?

OK, I finally got my lazy self to finish this series.  Recall that this is the third in a set of single issue newsletters on medical advances and healthcare policy.

 

To recap,

 

Object Lesson 1 on Ginkgo biloba was, it is “untenable to recommend a drug or nutraceutical in the absence of efficacy evidence simply because it could possibly help and initially appears harmless.”

 

Object Lesson 2 on healthcare systems around the world was, “an affordable and accessible healthcare system requires attention to underlying forces in the delivery of medical care.  Universal coverage cannot be sustained without it.”

 

Supplement:  1. The Obama administration has been doing a lot of work to publish roundtables and solicit input on policy issues that follows up on their promise of change and openness.  However, remember that the Clinton administration promised something similar, and then Hilary met in secret on healthcare reform and refused to release the deliberations of her working group.  This, along with the industry’s ad campaign undermined any chance for success.

  1. If you look at the details of the incoming administration’s healthcare reform package, it’s starting to look more like the McCain plan.  Healthcare policy experts criticized the plan proposed by the campaign as too much regulation and unsustainable spending.  It’s my belief that they are trying to meet in the middle somewhere.  However, nothing I’ve seen so far will, in my opinion, achieve the cost savings they anticipate.  You can review their public offerings here:  http://change.gov/agenda/health_care_agenda/
  2. Maybe you saw the NPR special on TV about the crisis in healthcare.  They made the case that in Massachusetts almost everybody is covered now, and were very upbeat about that achievement…however, they pointed out at only 3%  of medical students are going into primary care, and others are leaving that type of practice, that waiting times are increasing steadily, and that costs are climbing at an even greater rate.  No expert or public official offered any plan to address access and cost as a result of their universal coverage law.

 

So, for me the jury is still out on Change.

 

Enough of that.  This is the third of the issues I wanted to review with you.  Most of you know that a recurring theme of mine has been that we are Scaring Ourselves to Death (SOTD).  We are told daily of new risks to our health, in very dramatic media stories.   Usually there is no comparison to other risks, and no data to substantiate the claims.  In those few cases, when data are presented, it’s misleading (“Cancer Deaths Are Increasing”).  Most of you also know that I’ve said that the jury award for silicone-filled breast implants that led to Dupont’s bankruptcy in 1995, the largest settlement in history at $5B, was unsubstantiated by any science…and that the Institute of Medicine issued a subsequent review in 1999 that continued to confirm this fact.  There is no evidence that silicone breast implants cause chronic disease (including cancer) in humans.

 

Now a well-designed study was reported that appears to refute my claim:  Anaplastic Large-Cell Lymphoma in Women With Breast Implants http://jama.ama-assn.org/cgi/content/full/300/17/2030?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&andorexacttitle=and&andorexacttitleabs=and&fulltext=silcone+breast+implants&andorexactfulltext=or&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT.  This is a free article, so you can read the whole thing.

 

Here’s how the media reported it:  “Study indicates silicone breast implants may increase women's risk of ALCL.  HealthDay (11/4, Gardner) reported, "Women with silicone breast implants may have a higher risk of developing a rare form of lymphoma," according to a study published in the Nov. 5 issue of the Journal of the American Medical Association.”

 

So, am I wrong?  Let’s see.

 

A previous study did not support the association of anaplastic large-cell lymphoma (ALCL) in breast implants…only 3 cases were found.  The strength of this study is that the ENTIRE population in the Netherlands was reviewed for any breast disease over 17 years (1990-2006).  We’re talking ~17 million people.  They found breast lymphoma in 389 women and 40 men (Yes, men can get breast cancer, but it’s rare as hen’s teeth.)  Of the 389 women, 11 had ALCL, and five of these had previous implants.  As you can see, this is a very rare disease:  the incidence rate is about 1 in 1 million.

 

There’s a lot of cellular biology here:  lymphomas break down into Hodgkin and non-Hodgkin types.  Of non-Hodgkin, those in the breast are a small percentage.  Of the breast non-Hodgkin, most are B-cell in origin…rarely T-cell—which is what ALCL is.  You can sort all that out if you want to, but it makes my head spin.   Leave it that we’re talking “exceedingly rare.” 

 

There’s a bunch of math and case-control comparisons.  You can dig through that if you want, but the bottom line is that the analysis shows an increased risk for women with breast implants.

 

On the downside, the weaknesses of the study are that women who get breast implants have been shown to be different from other women in child-bearing age, residency patters, socioeconomic status, and access to care.  None of these factors were controlled in the study.   No comparison was made for other chemical (or sun) exposure, diet, or alcohol consumption (other common risk factors) .  Also if you look at the math, the confidence intervals (CI) for the experimental groups were HUGE (typical for very rare things).  This reduces the statistical power of the results.

 

So, forget the data:  does this association pass the common sense test?  Silicone is immunogenic (so are many compounds and medicines).  Could it cause a reaction that leads to a specific type of cancer over time?  In this study 3 of the five cases occurred 1, 3 and 4 years after implant.  Is that long enough?  Most would say, “doubtful” when you compare other chronic inflammatory processes.

 

As on reviewer said, “It is more likely that a compilation of infections, autoimmunity, genetic host susceptibility, and environmental and lifestyle factors will identify the most robust predictors of lymphoma risk.”

 

I don’t think I’m wrong. 

 

Things are always more complicated, aren’t they?  If you’re still with me, I’m finally getting to my point.  In science, we informally refer to the “One-In-A-Million (OIAM) Limitation”:  any event that occurs at the rate of one in a million or less, is practically impossible to prove because the number of potential confounding factors is usually huge, and the number of experimental subjects you need to have exceeds the number of humans currently living on the planet (some exaggeration for emphasis).  This leads to a corollary to the OIAM Limitation:  any risk at this level or below, even if provable, is so far down the list of measurable risks as to be unworthy of our attention (being struck by lightning, or a meteor, may be more likely).  To pay any attention to it is SOTD.

 

That’s Object Lesson 3:  For some exposures, actual risk to health and safety may be so low as to preclude consideration.  If you’re playing the odds, you need to pay attention to the thousands of influences in your life that are more of a risk.  If fact, I would recommend you come up with your Top Ten risk list.  If you succeed in modifying only those, you’re way ahead…and a lot less scared to death.

 

 

Medical quote of the Day:

One of the first duties of the physician is to educate the masses not to take medicine.—William Osler [1849-1919]

 

Doc D

Opinions are entirely my own.  Quotations from Kaiser Daily Health Policy Report ( © Kaiser Family Foundation), PND News Briefs – Texas Edition ( © 2008, Physician's News Digest, Inc.), AMA Morning Rounds (© U S News Custom Briefings), and other sources in the public domain.  As always, you may share this column, with appropriate attribution (here and in the text) included.  A special thanks to John Stossel for coining the phrase “Scaring Ourselves to Death.”

 

 

No comments:

Post a Comment

Followers

What I'm Reading - Updated 3 May