Plink Tank

Judging from media reports, soy is a regular Dr. Jekyll-and-Mr. Hyde of foods: on the one hand,jekyll it’s widely praised as a heart- and environment-healthy alternative to meat, and a source of important micronutrients like folate (particularly important for nursing mothers). On the other hand, it contains phytoestrogens – plant compounds that mimic, to varying degrees, the female hormone estrogen. Oncologists routinely caution breast cancer patients to consume soy in moderation or avoid it entirely. Nutritionists alternate between praising its virtues and warning against overconsumption.

Two recent studies have only added to the understandable public confusion around the safety of soy. First, a large, prospective epidemiological study in China reported that breast cancer survivors who consumed the most soy showed no greater mortality or relapse rate than those who ate the least soy. In fact, there was a statistically weak benefit for the soy lovers. On the other hand, researchers at the National Toxicology Program (NTP, a US Department of Health and Human Services program) issued a cautionary report and call for more research on the safety of soy-based baby formula, raising concerns that exposure to the concentrated soy extracts in the formulas may have detrimental effect on developing infants. Read More »

Posted in Uncategorized | Leave a comment

coinToss

Thank you Gary Schwitzer for addressing absolute versus relative risk, despite the media’s (and some researchers’) viewing the Tamoxifen issue as proof of patients’ stupidity.

I’m going to start with the conclusion of the New York Times column that inspired this commentary, in which a doctor at Memorial Sloane-Kettering dismisses the Tamoxifen problem as something that will be solved by aromatase inhibitors, the new generation of anti-estrogen therapy. I have news for the oncology community: aromatase inhibitors won’t change a thing.

Women don’t take these pills, and doctors don’t understand why, because they each hold a very different view of their costs and benefits. I used the term costs rather than risks for a reason, because this has very little to do with women over-rating the rare fatal side effects (those are a factor, but they’re not the factor). To explain, let me start with a simple cost-benefit matrix since, unlike a risk tolerance matrix, it puts a different emphasis on probability:

riskben

A typical risk tolerance grid, which is what seems to drive oncology research, says, in a nutshell, that the bigger the harm, the more risk averse we become, and the more we’ll do to avoid it (the upper right hand corner in that kind of matrix is usually an angry red). But in a cost-benefit matrix, this quadrant merely represents big gains in exchange for big costs. If the gains minus the costs are a wash, most people would rationally be neutral; so, the difference between the gain and the cost, or the probability of achieving the gain (or incurring the cost) become crucial.

When researchers broadcast juicy numbers about population risk and a risk-reducing drug, they’re almost always describing the bottom right-hand corner (huge benefit, small sacrifice), and almost as frequently understating the full costs as well as overstating the benefits. This New York Times column is a typical example. I can forgive anyone who read that column and came away thinking that taking Tamoxifen is a no-brainer and that patients are fuzzy headed at best.

Read More »

Posted in Uncategorized | Leave a comment

who doesn't abhor a vacuum?

who doesn't abhor a vacuum?

I woke up this morning with a mammogram debate hangover. Enough with the new guidelines, already! But still, what do we do with the mammogram-shaped holes in our lives?

As it turns out, nature abhors a vacuum almost as much as I do, and there are already some interesting and, fingers crossed and lucky rabbit’s foot in hand, promising developments on the horizon. One of the most interesting is the recent research into microRNA. This type of protein molecule could lead to more accurate cancer screening than lousy mammograms or the crude bio-markers we have today, like PSA (for prostate cancer) and CA 15.3 (for breast cancer).

What’s miRNA?

Think back to your high school biology class… OK, too far? Then think back to the advent of biotechnology, and the massive Human Genome Project, and how companies like Genentech and Amgen were going to cure cancer and generate new organs and allow us to live forever. Heady days! Someone made a killing in the market, no doubt. As for the rest of us…. Read More »

Posted in Breast Cancer, Uncategorized | Leave a comment

The New York Times ran this somewhat smug discussion of the new mammography guidelines, in which the author suggests that women dismiss the guidelines because they are confused or overly emotional. Hmmmm. Hard Truth + Silly Women = Hysteria. Where have I heard that argument before? Oh yeah, all of human history — the parts not written by women, anyway. Without addressing the data that lead to the new guidelines, I’d like to simply offer a few clarifying points for the scientists who are so befuddled by the reaction:

Imagine that you’re a health consumer. It’s not that difficult, there are only a couple of details you need to muster: (1) that you’re concerned about breast cancer, the number 1 killer of women aged 15-59, and (2) that the medical experts have insisted, throughout your entire post-adolescent life, that mammograms do indeed save lives. So although the tests are a gawd awful humiliating misery, you subject yourself to them annually, or plan on doing so when you’re older.

Never mind!

Never mind!

Then one year, these same medical experts take another look at the data during a tense debate on medical costs and issue a Rosanne Rosannadanna-style “Oh. Never mind.” And this “never mind” happens in the same year in which other experts say, Hey, you know that BPA that we insisted is perfectly safe? Well we’re rethinking that. And, uh, sorry about possibly predisposing you or your children to cancer.

And by coincidence the mammogram Never-Mind also happened just a few years after those same medical experts did an epic flip flop on hormone replacement therapy (HRT). That Never Mind came after years of selling HRT as the new fountain of youth that would stave off hot flashes, sleep problems, alzheimers, heart disease, and would pretty much usher us into health nirvana well into old age.

Getting back to the mammography guidelines: last month, the radiology and breast imaging director at my regional cancer center (a National Cancer Institutes affiliated clinic) came out strongly in favor of women aged 40 to 49 continuing to have annual mammograms. There’s more than enough debate among the experts out there to justify any woman deciding she’d just as soon keep her options open for now. Read More »

Posted in Breast Cancer, Plink | Leave a comment

Earth to public health pundits: you can’t correct one extreme by swinging to the opposite extreme.

Here’s a super-important issue that this whole mammography debate is only glancing off: no one is offering anything to pre-menopausal women. Yes, I understand that the epidemiology shows little or no benefit. Yes, I understand that (1) the benefits of mammography were grossly oversold, and (2) the risks were grossly understated. Those were preventable mistakes, by the way (don’t get me started on the failure of our medical system to provide breast health specialists).

But, epidemiology aside, if you spend a month in the infusion center at any cancer clinic, you will meet women in their 30’s and 40’s with terminal breast cancer precisely because their doctors pooh-poohed the mammo (”you’re too young for breast cancer”). No amount of epidemiology or number crunching can get around the fact that, for some women, mammograms DO save lives, or at least breasts.

What the debate is mostly ignoring so far is this: that there’s a difference between public health recommendations and personal choice, but that in our current regulatory and insurance atmosphere, decisions in the public realm can obliterate choices in the second. Epidemiology is an important input into public health decision making, but is not the final answer in personal decision making, especially when our tools for identifying “high risk” women suck even worse than mammography. Are you Ashkenazi Jewish? No? Then no mammo for you. That’s what our individual risk assessment tools boil down to – BRCA. The cause of maybe 10% of breast cancers.

My two cents (okay, maybe this is four cents):

(1) There are still excellent reasons to get a mammo under the age of 49 (lost in the population data is the fact that some lives and breasts ARE saved), and

(2) doctors have been worse than abysmal at understanding and communicating the risks, and

(3) women under 50 should be allowed to choose and should be offered the information needed to choose intelligently, but

(4) the task force recommendations will likely eliminate this choice by leading insurers to drop pre-meno mammo coverage like a nuclear potato.

All of which makes me sad, and worried, that if the choice to obtain a mammogram is taken away from pre-menopausal women, that there will be more women like the ones I met at the cancer clinic.

Medicine has done an abysmally poor job at explaining the risks and benefits of mammograms to pre-meno women. But the answer to that failure isn’t to abandon this population altogether. That’s just swinging from one simplistic extreme to another.

Posted in Breast Cancer, Health Care Reform | Leave a comment

Endocrine disrupters are chemicals that mimic the hormones in our bodies (often estrogen), and just like the natural versions, they cause our cells to stop, start, or change their functions. Exposure to these chemicals is known to cause birth defects, cancer, and a host of other health problems in animals, and is suspected of doing the same to people. Still, plenty of people, but especially the chemical industry, will tell you that these chemicals are perfectly safe at the levels at which we’re exposed.

The problem and source of controversy is two-fold: (1) no one really knows how much we’re exposed, and recent pilot studies indicate that it’s a lot more than the chemical industry claims, and (2) if you decide you would rather play it safe while more research is conducted, too bad. The industry and government have already decided for you that you’re going to get lots and lots of these chemicals in almost every product you buy.

Is this a cause for panic?  Better to say it’s a cause for getting off your comfy assumptions and getting involved. Too busy or confused?  Join the party, and here’s some motivation to help with that:

Read More »

Posted in Breast Cancer, Environment and Health | 5 Comments

How much would you have in common with this test subject?

How much would you have in common with this test subject?

The next time a health news report is causing you excessive worry (or manic optimism), when they’ve dodged your goo tool, and perhaps even your size matters tool — when some editor is rubbing his hands in glee convinced that they’ve got you this time because the study involved people, and lots of them — your should instead turn up your nose and sniff, “Yes, dahling, but what kind of people?”

This isn’t simply about channelling Leona Helmsley, although that can be fun. What I’m getting at is that the nature of test subjects matters as much as their number. The quality of a human study is based in part on how the participants were selected, and their characteristics. It’s not so much whether the participants are normal (whatever that means), as whether they are like you.

Read More »

Posted in Toolkit | Leave a comment

From time to time, when I’m swamped at work and flunking out of social life 101, I have a tendency to say “awww, phooey” to the Big Issues, like health care reform and environmental stewardship. I figure someone else can worry about ‘em for a while. When that happens, all it takes to reignite a bonfire under my butt is a few minutes’ browsing on the Environmental Health Perspectives website. This month’s issue has a powerful reminder about how complacency kills: a report showing strong links between prostate cancer and blood levels of certain pesticides.

The full article can be downloaded here, but I’ll provide a few highlights:

The study (sponsored by the NIEHS, or National Institute of Environmental Health Sciences) looked at several different organochlorine pesticides, of which the most well known is DDT. The link between DDT and cancer has been investigated in the past, with mixed results. The NIEHS study addressed several of the limitations of previous studies, including (drum roll, and link to Health News Tool #3), the kind of people studied. Among other flaws, past studies involved pools of individuals who were not representative of the general public (for example, farm workers, who had a greater-than-average exposure) or used measures that failed to adequately reflect exposure to the pesticide.

Should Mr. Yuk appear on blood transfusions?

Should Mr. Yuk appear on blood transfusions?

In addition to addressing these weaknesses, the NIEHS study looked at the association between prostate (and breast) cancer for several pesticides individually, and at different exposure levels (using actual blood concentrations as measure of exposure). What they found was a distinct association between blood levels of each pesticide and development of prostate cancer. The higher the blood levels, the greater the prevalence of prostate cancer. Not all pesticides were the same — some showed a weaker link, but for some pesticides the prevalence of prostate cancer increased three-fold at the highest blood concentrations.

Now, I don’t know about you, but I can’t recall the last time anyone even used the acronym “DDT” in a sentence. DDT was banned nearly 40 years ago in the United States, yet continues to persist in our environment, to pollute our food and water, and quite possibly to promote cancer, despite decades of wrangling over its “cost-benefit profile”. Not only does it frustrate me that our health is still being threatened by pesticides abandoned more than a generation ago, but it makes me view the current debates over everything from Bisphenol A to Round-Up Ready Soybeans with a more-than-jaundiced eye.

Posted in Environment and Health | Leave a comment

A year and a half ago, I found myself strapped to a backboard in the back of an ambulance, unable to answer a simple question. My car had been totaled by a driver who was too important for red lights, giving me what a yogi would describe as a perfect opportunity to practice “just being”. But then the paramedic riding with me explained that the major trauma hospital was turning away arrivals due to workload, and he wanted to know which of the other two major hospitals they should take me to.

In that moment I realized that I had absolutely no basis for choosing between them. I flashed on recent incidents, one at each hospital, in which a patient was killed through stupid and preventable error (for example, by injection of improperly labeled cleaning fluid instead of MRI contrast agent). And I recalled at least one near-fatal horror story for each hospital from friends and colleagues. I wasn’t thrilled about trusting my life to either, and certainly had no basis for choosing between them. So there I was, in not a little pain and with an ever-so-gradually collapsing lung, at a loss for choice in what is supposed to be a thriving, consumer-choice-enhancing free market for health care services.
Read More »

Posted in Health Care Reform | Leave a comment

FoghornChickenhawkRemember Henery Hawk, that little chicken hawk who was always pestering Foghorn Leghorn? That’s the image that should come to mind the next time you read of a little 12-person (or 20-rat, or 40-mouse) study claiming to have found a cure for cancer, wrinkles, or even boredom. It’s not that small studies are worthless (they’re not), it’s that they’re worthless for making Big Decisions about treatment, lifestyle, risk, or where to spend your money. The reason for this, in layman’s terms, is chance.

When a research study sets out to really prove or disprove something, it enlists hundreds or thousands of participants. This makes the study very, very expensive. A small army of health professionals, administrative staff, software engineers, and research assistants are needed to train, treat, and track that many participants. Why go to all that expense, all the grant writing and organizing and stress and strain? Because it’s the only way to rule out chance or, as epidemiologists like to call it, sampling error
. Read More »

Posted in Toolkit, Uncategorized | 2 Comments

tweet feed