Cancer: Panel Finds Environmental Risks Neglected

[Guest guest]

Is the President's Cancer Panel report, called Reducing Environmental Cancer Risk: What We Can Do Now, reasonable?

"Thun finds last week's report "unbalanced" because of its "dismissal" of cancer prevention focused on lifestyle factors such as smoking and obesity that make a much larger contribution to cancer incidence."

Science 14 May 2010:Vol. 328. no. 5980, p. 802News of the WeekCancer: Panel Finds Environmental Risks NeglectedJocelyn Kaiser

A flap has erupted among health experts over a report last week from a presidential advisory group that concludes environmental pollutants are an underappreciated cause of cancer that is inflicting "grievous harm" on Americans. The report, from the President's Cancer Panel, has drawn fire both from an industry-leaning group and from the mainstream American Cancer Society (ACS) for distorting environmental cancer risks.

One of the report's authors, Margaret Kripke, an immunologist and professor emeritus at MD Cancer Center in Houston, Texas, acknowledges that the text is "deliberately thought-provoking" but defends its scientific rigor. "Part of the issue here is to stimulate a call to action, and you don't get that by having a bland" report, Kripke says. She is one of the two members of the authoring panel; the other is LaSalle Leffall, a surgeon at University. A third member, cancer activist Lance Armstrong, who did not contribute to the report, left the panel in 2008 and was not replaced.

Thought provoking. Co-author Margaret Kripke did not want a report on cancer risks to be bland.CREDIT (RIGHT): MD ANDERSON

The 240-page report, called Reducing Environmental Cancer Risk: What We Can Do Now, states that "the true burden of environmentally induced cancer has been grossly underestimated" and that Americans "are bombarded continually with myriad combinations" of carcinogenic pollutants. It reviews exposures from a range of sources, including hot-button ones such as the plastics ingredient bisphenol-A, medical x-rays, and even cell phones. Among other recommendations, it urges people to use headsets with cell phones and recommends that Congress and the president adopt the "precautionary approach," which would require manufacturers to demonstrate the safety of chemicals before distributing them on the market.

The American Council on Science and Health, a nonprofit organization with industry support, wrote that "the report practically plagiarizes the work of anti-chemical activist groups" including the Environmental Working Group (EWG), an environmental advocacy organization in Washington, D.C. EWG's Wiles was one of 45 witnesses—including many government and academic scientists—who spoke before the presidential panel in 2008 and early 2009.

Among those who object to the report's conclusions is ACS's emeritus chief epidemiologist, Thun. In a response last week, Thun wrote that ACS had issued a report on environmental risks last year that raised similar concerns about untested chemicals, the risks to children, and hazards of medical imaging. But Thun finds last week's report "unbalanced" because of its "dismissal" of cancer prevention focused on lifestyle factors such as smoking and obesity that make a much larger contribution to cancer incidence. Thun also disputed the report's claim that estimates of pollution-induced cancer are "woefully out of date," asserting that this statement "reflects one side of a scientific debate."

That debate centers on the low estimates in 1981 from University of Oxford epidemiologists Doll and Peto, who found that occupational exposures and pollution cause about 6% of cancers. Boston University epidemiologist Clapp, who testified before the presidential panel, acknowledges that he and a few other academics have contested the Doll-Peto figures and have been at odds with ACS on the issue for years.

Peto, for his part, says the report's criticisms of his and Doll's methodology are familiar and "factually untrue." He says, "I don't think there's any good reason to revise our estimates upward."

The President's Cancer Panel, created by the 1971 Cancer Act, is independent, although staffed by a small office at the National Cancer Institute. A science writer compiles testimony and the panelists' own input and writes the report, says the panel's special assistant, Burt. The report does not go through peer review, but staff fact-check the information, she said. She defends the report as "very measured."

Kripke says she's "disappointed" by ACS's criticisms. She says they're ignoring previous reports from the same panel emphasizing the importance of lifestyle factors. As for the Doll and Peto estimates, she says the view that they need updating is "an opinion."

Activists are hoping the report will spur efforts in Congress to make U.S. chemical safety regulations more consistent with the precautionary principle. But it's not clear whether the proposal will gain much momentum. Its immediate destiny is to join a shelf full of previous annual reports from this panel.

-- Al Pater, alpater@...