Most of the recent media conversation about breast cancer prevention has concerned the topic of screening, and whether and when mammography is routinely appropriate.
Last week, the Institute of Medicine (IOM), a National Academy of Science panel that advises government and the public on issues of health and medicine, garnered front-page headlines with its study about risks for breast cancer. In comparison to most media outlets, which took a “Now Hear This!” approach, the New York Times‘ coverage seemed … underwhelming.
“An exhaustive new report meant to address public fears about possible links between breast cancer and the environment,” it began, “finds evidence strong enough to make only a few firm recommendations, most already well known and none with a large proven benefit.”
Where some media framed the report’s conclusion as-if not revelatory, at least significant-The Times was measured. After enumerating the factors that appear to contribute to increased risk of the disease, The Gray Lady suggested that people in search of definitive information about exposure to chemicals, pollution, cosmetics and drinking water would be disappointed. The report, the paper said, “is based largely on a review of existing research, and its limited advice reflects the lack of solid scientific information in many areas of concern to the public.”
Subsidized by $1 million from Susan G. Komen for the Cure, an advocacy group dedicated to eradicating breast cancer, the IOM committee’s chairwoman said it could not “identify a bunch of environmental factors” that might contribute to breast cancer.
According to the report, data did indicate that women could reduce their risk by limiting or avoiding:
- unnecessary medical radiation;
- hormone treatments that combine estrogen and progestin;
- alcohol consumption; and
- weight gain (especially for postmenopausal women).
Weaker evidence, according to the report, suggested that not smoking and increasing exercise lowered risk for breast cancer, and there were a “possible associations” between breast cancer and secondhand smoke, nighttime shift work and exposures to the chemicals benzene, ethylene oxide and 1,3-butadiene (component of car exhaust, gasoline fumes and tobacco smoke).
Even weaker evidence, defined as “biological plausibility,” was identified in certain substances including the chemical bisphenol A (BPA), found in some plastic containers, can liners, food packaging and other products.
In terms of radiation, the report called out the overuse of CT scans, which deliver relatively higher doses of radiation. But it did say that mammograms, which deliver smaller doses, are not of concern.
Cancer in general is a hot medical topic because of its intractability, its invasive and side-effect inducing treatments, its many varieties and the massive amounts of dollars devoted to its treatment and eradication. So any news that seems to be maybe groundbreaking often is translated by the media as definitely groundbreaking.
This news isn’t.
The Times describes why. The disease is difficult to study because suspect chemicals cannot ethically be given to people to see if they cause cancer, and studying people who were exposed in the past yields unreliable information about the dose and timing. Animal studies don’t always apply to humans. And people are exposed to various mixtures of chemicals that may interact differently and with effects that may also vary according to an individual’s genetic makeup.
Also, the panel noted that the effects of various environmental exposures differ depending on someone’s age. Breast tissue may be affected differently in the womb, during childhood, adolescence and adulthood and before and after pregnancy. To state definitively that a certain chemical in a certain environment will pose a certain risk to all breast tissue is false and irresponsible.
The IOC panel noted that even if a woman is scrupulous in eliminating the outlined risks, her risk is subject to the usual vagaries of cancer. “The potential risk reductions from any of these actions for any individual woman will vary and may be modest.”
And some of the behaviors to be avoided might be helpful if someone is facing a different disorder or disease. Moderate drinking might help prevent heart disease; if someone forgoes a CT scan, she might deny herself a valuable diagnostic tool.
As always in the face of breathless medical “news” reporting, before you swallow the message, read the whole story.