Breast Cancer’s Chemical Culprits

If you have breasts, you are probably interested in any news about preventable causes of breast cancer, which hits one in eight women. I’ve always felt frustrated that the public discussion around prevention tends to emphasize lifestyle choices and heredity more than possible environmental links– that is, the role of industrial chemicals, toxic emissions, and so on. The disconnect is odd, considering that these poisons have been implicated in other forms of cancer.

So last week I was at once horrified, encouraged, and frustrated by a page-one Los Angeles Times article headlined “Common Chemicals Are Linked to Breast Cancer” (5/14/07) by award-winning environmental reporter Marla Cone.

I was horrified by the information it provided:

“More than 200 chemicals – many found in urban air and everyday consumer products—cause breast cancer in lab animals, according to a compilation of scientific reports published today. Writing in a publication of the American Cancer Society, researchers concluded that reducing exposure to the compounds could prevent many women from developing the disease [italics added].”

Here are the highlights of Cone’s carefully reported story, which summarizes the results of this “review of hundreds of existing studies and databases”:

-Of the 216 chemicals that induced breast tumors in lab animals, humans are “highly exposed” to 97. Many of the substances are found in or near the home, and include (among other things) ingredients in pesticides, cosmetics, and pharmaceuticals, along with compounds in vehicle exhaust. Seventy-three of the chemicals are found in consumer products or are food contaminants. What’s more, the researchers said, there are probably many more than 216 breast-cancer-promoting chemicals out there, “because only about 1,000 of the 80,000 chemicals registered for use in the United States have been tested on animals to see whether they induce cancerous tumors…”

-The federal government typically does not use such animal breast-cancer data in assessing risks to humans, nor in setting occupational health standards. But toxicologists and the study’s authors say that animal tests on mammals, who develop the same tumors people do, are a proven way to test chemical effects. Moreover, some of the chemicals found to be breast carcinogens are not yet regulated.

-The body of evidence about breast cancer’s causes suggests that the disease begins in infancy or even earlier, so more research should focus on early chemical exposures.

-The etiology of breast cancer is indeed complex, “probably triggered by an interaction of multiple environmental and genetic factors,” and some people may be more susceptible than others to chemical exposures. Due to this very complexity– according to the (female) science and health experts quoted in Cone’s article – it would be wise to take precautionary measures such as reducing one’s exposure to the 216 chemicals.

No Legs
I was encouraged that, with this article’s appearance in a prominent newspaper, a door may have been opened into further discourse about public health and new research into the environmental factors behind this “leading killer of US women in their late 30s to early 50s.” Indeed, the study’s funder, the Susan G. Komen for the Cure, just committed $5 million for further research on the environment-breast cancer connection.

But I was frustrated by the lack of “legs” the story seems to have had in the mainstream press. As of May 21, a Lexis-Nexis search showed Cone’s piece had been picked up or summarized by only the Baltimore Sun, the Charleston (WV) Daily Mail, Grand Rapids (MI) Press, UPI, and the Washington Times; there was also an editorial in the San Francisco Chronicle. It’s been discussed on some, but not all, of the more prominent feminist media websites, suggesting not a lack of interest in Cone’s article but that it’s somehow flown under the radar.

Not the First Time
In writing this post, I want to ensure that “Common Chemicals Are Linked to Breast Cancer” doesn’t meet the same fate as another eye-opening report of closely related findings that was published a year and a half ago. “State of the Evidence 2006: What Is the Connection Between the Environment and Breast Cancer?”, compiled by the San Francisco-based Breast Cancer Fund, surveyed the scientific studies on breast cancer in humans, not lab animals. It found that half of all breast cancers could not be traced to lifestyle choices or heredity, and said there was strong scientific evidence of an environmental component, such as radiation and/or synthetic chemicals, which act by “altering hormone function or gene expression [italics added].”

Despite this stunning news, mainstream media coverage of “State of the Evidence” appeared in only a handful of California and other mostly regional papers; then it virtually ceased. Granted, the BCF is an advocacy group. But BCF’s report focused on the work not of its own staff scientists but a broad swath of pre-existing, independent scientific studies, and was peer-reviewed by scientists at major research universities. The more recent breast cancer/chemical survey appeared in Cancer, a publication of the American Cancer Society. In other words, the sourcing was as establishmentarian as one could want.

What might account for the lack of buzz around these stories? Are the news media afraid to alienate advertisers who produce all those chemical- based products? Or is the wider implication too challenging to contemplate? Namely, that the chemical soup we swim in is harming not just Earth’s atmosphere but our own bodies?

Keep the Discussion Going
The public could benefit from much more mainstream coverage of breast cancer from a public-health angle (versus the current individualized focus). Such an approach would probe the role of current and past toxic exposures and chemical “body burden” in breast cancer. There could be far more discussion of the precautionary principle — which says evidence, not proof, of harm should guide our actions. And when reporting on breast cancer, the press should also more closely follow current and proposed legislation around related issues, such as product testing and occupational safety.

Let’s face it: While progressive media and environmental magazines have been following the environment/cancer connection for years, in America the kitchen-table conversations still don’t really start until well-known mass media spotlight the issues.

Backpedaling?
Meanwhile, The LA Times itself seemed to be backing off Cone’s story, judging from a piece it published a week after hers (5/21/07). “A Closer Look: Chemicals and Breast Cancer,” a special report by Mary Beckman, seemed intended not so much to debunk that article as to reassure the public. It was subheaded “Suspects, but not all perps; A report has linked chemicals to tumors in animals. But the risks to women are less clear,” and stated:

“[The report’s findings do] not mean women should stop cooking with canola or cower indoors for fear of getting breast cancer, experts say. Although some scientists would like to see levels of many of the listed contaminants reduced in the environment, the list is more of a starting point for researchers to investigate further.”

Later, it noted, “The animal carcinogen database is not meant as a guideline for the general public to avoid certain chemicals, the authors say. But some researchers think the public might take it that way — and place more stock in it than they should.”

To its credit, Backman’s piece couched the study’s findings and methodology in the context of the larger cancer-research picture. But it so emphasized uncertainty as to subtly dismiss the chemical-cancer connection. For example, it declared, “The 216 chemicals are not the only or even the most important breast cancer worry.” And some of the caveats it raised were already addressed in Cone’s piece, such as a comment that animal data don’t necessarily apply to humans.

We may still be a ways from understanding the roots of breast cancer. But now that more evidence points to environmental triggers, I hope reporters and the general public alike will press further on those who shrug that all we can do is eat our broccoli, get our mammograms, and cross our fingers.

This post is dedicated to Peggy Gazawi (1958-2002) and Leslie Godley (1956-2007).

This entry was posted on Thursday, May 24th, 2007 at 8:11 am and is filed under Environment, Health & Sexuality, Science, Issues in the News. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.