What Causes Breast Cancer? Reviewing the IOM Report on BC and the Environment

Earlier this month the IOM issued a big report on breast cancer and the environment. The thick analysis, commissioned and sponsored by the Susan G. Komen for the Cure®, was authored by an expert panel. Their task – to assess all available information on what causes BC, and make recommendations accordingly – was essentially impossible. Some immediately critiqued the work and, perhaps implicitly, the funding – for its failure to yield sharp or clearly-actionable insights into BC causes.

The document starts, blandly, with some straightforward stuff. The recommendations for lifestyle changes seem paternalistic when not obvious. Where the report gets interesting, and offers value, is in considering a few specific environmental toxins that might be causative in the current breast cancer epidemic. While proving that any one (or several) of the chemicals listed below causes  BC will be difficult, developing a clear, working list of likely compounds that merit research attention is an important step.

Some background:

Each year, over 230,000 women in the U.S. develop a breast tumor. The problem, in terms of preventing breast cancer, is that most established risk factors – like being older, later age at menopause, being young at the time of first menstruation and some genetic traits – aren’t amenable to intervention.

For this project, the IOM committee interpreted the term “environment” broadly – it considered all possible causes of BC that aren’t directly inherited through DNA, including factors that might influence a genetic disposition. They looked at a wide range of exposures: “how a woman grows and develops during her lifetime; what she eats and drinks; the physical, chemical, and microbial agents she encounters; how much physical activity she engages in; medical treatments and interventions she undergoes; and social and cultural practices…”

What they found, with my comments interspersed and conclusions:

The most convincing evidence linked BC to hormone therapy with estrogen and progesterins, ionizing radiation (as might occur in medical procedures like CT scans; the amount of radiation in mammography is too low for concern, the committee emphasizes), excess weight (i.e. being fat, or more-than-fat) in postmenopausal women, and alcohol (addressed here, previously).

Where they found no clear link: smoking (surprise! the evidence is limited, they say), personal use of hair dyes, non-ionizing radiation (like that emitted by microwaves and other electrical devices).

On the up side: Physical activity appears to lessen a woman’s breast cancer risk.

Quite a few factors fell into a gray zone, for which “the evidence is less persuasive but suggests a possible association with increased risk.” These are: exposure to secondhand smoke (this might be a cause, but smoking isn’t? seems unlikely, ES), nighttime shift work (steroids/stress effect? Or just too much junk food).

Finally, they name some chemicals: benzene, ethylene oxide, or 1,3-butadiene (these may be present in some workplaces; one might be exposed from breathing auto exhaust, pumping gas, or inhaling tobacco smoke, they indicate) and bipsphenol A (BPA) – one of the “biologically plausible hazards in the environment.” As they indicate, animal data provide clear evidence for a mechanism by which BPA, which is widely-used in plastic containers and food packaging, might cause breast cancer. “But studies to assess the risk in humans are lacking or inadequate.”

The IOM committee study authors consider the difficulties in testing environmental hazards. Of course, as they point out, it wouldn’t be ethical to deliberately expose women to potentially harmful substances in a clinical trial. For this reason, they advocate more research in animals and in vitro systems. But those kinds of experiments are limited, in their words: “they can provide indications that a chemical or other agent may cause harm, but these models are approximations of human experience.”

So we’re stuck with a lot of inconclusive data, and an obvious moral imperative not to systematically test the effects of possible environmental toxins on women who might develop BC. There’s a table posted, with strategies to reduce risk, but it recommends for the most part obvious things, and an annoyingly-toned paragraph:

These actions include avoiding unnecessary medical radiation throughout life, avoiding use of postmenopausal hormone therapy that combines estrogen and progestin, avoiding smoking, limiting alcohol consumption, increasing physical activity, and, particularly for postmenopausal breast cancer, minimizing weight gain. Some of these actions may have additional health benefits beyond their potential contribution to reducing breast cancer risk. In many cases, women can be aided by the actions of others, including their families and health care providers.

(Why don’t they just say: “be a good girl, get rest, and stay slim?”)

The segment on the future and needed research emphasizes the need for research on early-life exposure to chemicals, pre-menopausal obesity, and other factors that may influence development of BC later on in a woman’s life. This makes sense to me.

The most troubling findings have to do with the chemicals. Carcinogens like benzene are hard to put a finger on, when it comes to causing cancer in a population where cars are abundant and oil leaks often, and occasionally abundantly, into large gulfs of water. The BPA issue is a genuine concern, with little clear data in humans. Until those data are evident (which, if it takes decades to show the effects on youngsters exposed who develop BC in, say, their 40s), will not be for a while – you have to wonder if doctors should recommend more drastic steps to avoid routine exposure to and ingestion of potentially toxic chemicals.

If you’d like to read about this report and some of the concerns about chemicals that might cause BC, I recommend this post by Julia Brody, of the Silent Spring Institute.

Related Posts:

Noting the Death of Christopher Hitchens from Esophageal Cancer

The author is saddened to learn that Christopher Hitchens died late yesterday evening at the age of 62, roughly a year and a half after receiving a diagnosis of esophageal cancer. He was a prolific and articulate man; I respected him for his words.

His essays on the language and cancer might be of particular interest to some readers of this blog.

The NCI reports there are some 17,000 new cases of esophageal cancer in North American each year; it’s not a common tumor, and most cases arise in men. The annual number of deaths from esophageal cancer approaches 15,000 in the U.S. These numbers are telling: it’s not an easy disease to have, or to treat.

——

Related Posts:

Why Should Physicians Blog or Use Twitter?

Is a question I ask myself almost every day. When I started this blog, it was partly a response to what I perceived an unbalanced attack on the value of breast cancer screening by the mainstream news outlets. Why it’s continued is, mainly, that I find it liberating and, in a strange way, fun. As I’m no longer practicing, this wide-open world of shared facts, some questionable, and new ideas keeps me alert and, maybe, in-touch.

Today several physicians tell of the benefits of social media for physicians. One post by my colleague Kevin MD is titled Bury Bad Doctor Reviews With a strong Social Media Presence. Kevin has, previously and elsewhere, described the potential value of blogs that encourage nuanced discussion of health care news. What he reveals, today, is that blogs can be a way for doctors to put forward a positive image of themselves and their practices. Closer to home, orthopedist Howard J. Luks, MD writes to the point: on social media, health and marketing.

But if that’s what doctors’ blogs are about, why don’t we just call it PR?

As I’ve said before, I do see value in academics blogging, especially if they’re not afraid to question, and don’t simply kiss up to authors who’ve published articles in major journals. I can see how Twitter from a trusted source like the CDC could be a rapid way to disseminate information about a new viral strain, an urgent need for blood donors, or a real public health emergency.

But for most practicing physicians, I just don’t see how they have time for it. Unless it’s like a hobby, or better – an open notebook – a way of recording your thoughts on what you’ve seen and learned in the day. That kind of blog can be great, even useful, for patients and other docs. The main thing is that the purpose of physicians’ and hospitals’ websites or blogs should be clear.

Recently I saw a tweet by @jamierauscher about whether she thinks to inform her docs about her use of social media. That’s a separate topic.

Later.

Related Posts:

Quote of the Day: On Death Panels and the Insurance Industry, From Dr. Donald Berwick

Dr. Donald Berwick left his position last week as head of CMS. He said this, as quoted in the WSJ’s Washington Wire, yesterday:

“Maybe a real death panel is a group of people who tell health care insurers that is it OK to take insurance away from people because they are sick or are at risk for becoming sick.”

I couldn’t agree with him more.

All for this week,

ES

Related Posts:

Learning From the San Antonio Breast Cancer Symposium, At a Distance

There’s a ton of BC and women’s health news this week. But yours truly is, among other things, not in San Antonio where is the 34th annual San Antonio Breast Cancer Symposium.

NTW, quite a few major news outlets are covering this business closely and carefully, as are some bloggers I know. Upon reading the news, I was simultaneously impressed by the number of new drugs for metastatic breast cancer that are being tried, and daunted upon realizing how difficult (read: IMPOSSIBLE) besides costly it’ll be to sort out these drugs used in so many combinations. Rather than recapitulating the data, some of which was published on-line this week in the NEJM, and most of which are still preliminary, I thought I’d just list some of the drugs being tested, and add a bit about how they’re administered and might work:

Entinostat is an oral histone deacetyalase (HDAC) inhibitor that’s not yet available in the US by any prescription off protocol.

Everolimus is a tablet (i.e. a pill) designed to inhibit an enzyme called mTOR. It’s sold for use in some cancers under the brand name Afinitor.

Exemestane is a tablet that reduces estrogen production. It’s an aromatase inhibitor sold as Aromasin. (This drug was approved by the FDA in 2005; it’s not quite so new, but is being tested in distinct settings, mainly in women with early-stage BC.)

Pertuzumab is a monoclonal antibody that binds Her2, in a distinct way from Herceptin.

Obviously this is but a partial list of drugs discussed at the meeting. Still, it’s heartening to this one oncologist to review even a short list of diverse new agents that might arrest the disease.

The history of the SABCS is interesting.  From the organization’s website:  the first meeting was held in November 11, 1978 during what’s said to have been “Breast Cancer Awareness Week.” The original conference’s sponsors included the Cancer Therapy and Research Center (CTRC, at UT San Antonio), the Texas Division of the ACS, the University of Texas Health Science Center at San Antonio (UTHSCSA) and the Bexar County Medical Society. Some 141 physicians and surgeons attended what’s described as one-day course.

It grew…

Now, the SABCS hosts a 5-day program with physicians, scientists, patients, advocates, reporters…from around the world. It’s jointly-sponsored by the CTRC and American Association for Cancer Research (AACR) and the Baylor College of Medicine.

The Alamo (WC image)

Next year, maybe I’ll go to the 35th annual event, and see what’s really happening in San Antonio.

Related Posts:

The BC Sisterhood Takes on Sex After Cancer and What Oncologists Don’t Say

A hit in the women’s breast cancer Twitter league came my way from the Breast Cancer Sisterhood®. Brenda Coffee, a survivor and founder of the Survivorship Media Network, offers a serious post on What Your Oncologist Doesn’t Tell You About Sex.

There’s a music video, Don’t Touch Me that’s annoying but depressingly right on how some women feel in menopause –  a frequent and under-discussed aspect of chemo or hormonal therapy for BC, followed by a grounded and unusually frank discussion about what happens to women after cancer treatment, menopause and sex.

Brenda’s right; none of this was included in my med school curriculum or oncology fellowship. Although, in fairness and quite seriously, this was a subject on mine and some other oncologists’ radar long ago. Cancer treatments can have lasting effects on sexuality in men and women.

Worth checking out Brenda’s network and her candid post. You can follow her @BCSisterhood on Twitter.

Related Posts:

Thinking of Someone with MBC in the Hospital Now

My fingers stopped this morning for a while when I came upon a reference to @whymommy. Last thing I read about her condition, she was at home having a tough but cozy Thanksgiving at home. Now she’s in the hospital and in her words, OK.

Susan is a woman in her 30s with metastatic breast cancer. People, including me, have described Susan as an astrophysicist, mom, wife… But the main thing is she’s a person.

Each counts.

Hope she gets to go home soon and feels better –

#EndBC

Related Posts:

A Good Personal Health Record is Hard to Find

Over the weekend I developed another bout of diverticulitis. Did the usual: fluids, antibiotics, rest, avoided going to the ER, cancelled travel plans.

One of my doctors asked a very simple question: is this happening more frequently? The answer, we both knew, was yes. But I don’t have a Personal Health Record (PHR) that in principle, through a few clicks, would give a time-frame graph of the bouts and severity of the episodes over the past several years.

The last time this happened, and the time before that, I thought I’d finally start a PHR. Like most compulsive patients, I keep records about my health. In the folder in my closet in a cheap old-fashioned filing box, the kind with a handled top that flips open, I’ve got an EKG from 15 years ago, an OR report from my spine surgery, copies of lab results that the ordering physicians chose to send me, path reports from my breasts, a skin lesion or two, and, more recently a colonic polyp, bone density studies from 2004, EMGs and more, essentially miscellaneous results.

None of the records I have are digital.

A few years back I considered using Google Health. But their service, as I understood it, involved scanning documents and uploading them to the Cloud, or paying someone else to do so. That sounded like a hassle. But even had I done that, I wouldn’t have been able to, say, see a graph of my hemoglobin since 1986, or something as simple as my weight changes over time. When Google Health folded a few months back, I was disappointed. At the same time, I breathed a sigh of relief that I hadn’t invested my personal and limited energies into putting my records there.

But now what?

I searched for a PHR, again on-line, and found some commercial stuff, mainly targeting doctors’ offices and larger health care systems. Medicare’s information on Managing Your Health Information Online offers bullet-point explanations on Why Use PHRs?

But I needed no convincing. What I need is software, or a platform, that’s user-friendly and secure. Ideally mine would mesh with my physicians’ records, but my doctors use a variety of record systems. So it’s up to me to integrate the data, if anyone will. The problem is there’s little out there, as best I can tell, that’s intended for patients. Most IT companies are, for now, focused on getting doctors to sign on.

So I’ll start an Excel spreadsheet, today, on my PC. There must be a better way.

Related Posts:

New Music from an Orchestra of Radioactive Isotopes

For the weekend –

A tweet led me to a fantastically inventive kind of music. The Radioactive Orchestra comprises 3175 radioisotopes. From the website: “Melodies are created by simulating what happens in the atomic nucleus when it decays from its excited nuclear state…Every isotope has a unique set of possible excited states and decay patterns…”

image from the Radioactive Orchestra project

The project, sponsored by a Swedish nuclear safety organization, KSU, encourages visitors to select among the graphed isotopes, listen and learn. You can try composing music on your own, or you can check out a production by DJ Alex Boman on YouTube:

Super-cool.

h/t: Maria Popova, @brainpicker, who picked up on this last August at Brainpickings. And to @JohnNosta, who sent yesterday’s tweet.

—-

Related Posts:

newsletter software
Get Adobe Flash player