Kevin Kuhn

Cancer Debate...What Do You Think?

Discussion created by Kevin Kuhn on May 7, 2010

The following item was recently posted on the act4chemistry.org blog.  What do you think?

 

The President's  Cancer Panel published their annual report yesterday.  The report (pdf), entitled "Reducing Environmental Cancer Risk, What We Can Do  Now", has spurred on an ongoing debate within the cancer sciences  community about the proportion of cancer caused by environmental hazard.
In a letter to the President, the Panel  presents a succinct  thesis of what they consider to be the problem:
Environmental exposures that increase the national cancer burden  do not represent a new front in the ongoing war on cancer. However, the  grievous harm from this group of carcinogens has not been addressed  adequately by the National Cancer Program. The American people—even  before they are born—are bombarded continually with myriad combinations  of these dangerous exposures. The Panel urges you most strongly to use  the power of your office to remove the carcinogens and other toxins from  our food, water, and air that needlessly increase health care costs,  cripple our Nation’s productivity, and devastate American lives.
In their coverage of the report, MSNBC  notes, however, that as many as two-thirds of cancer cases are  caused by lifestyle choices like smoking, poor diet and lack of  exercise.
The American Cancer Society has a similar perspective.   According to the New York Times article  on the disagreement:
The cancer society estimates that about 6 percent of all  cancers in the United States — 34,000 cases a year — are related to  environmental causes (4 percent from occupational exposures, 2 percent  from the community or other settings).
In an online  statement, Dr. Michael Thun, an epidemiologist from the cancer  society, had this to say:
Unfortunately, the perspective of the report is unbalanced by  its implication that pollution is the major cause of cancer, and by its  dismissal of cancer prevention efforts aimed at the major known causes  of cancer (tobacco, obesity, alcohol, infections, hormones, sunlight) as  “focussed narrowly.”
The report is most provocative when it restates hypotheses as  if they were established facts.  For example, its conclusion that “the  true burden of environmentally (i.e. pollution) induced cancer has been  grossly underestimated” does not represent scientific consensus.   Rather, it reflects one side of a scientific debate that has continued  for almost 30 years.
There is no doubt that environmental pollution is critically  important to the health of humans and the planet.  However, it would be  unfortunate if the effect of this report were to trivialize the  importance of other modifiable risk factors that, at present, offer the  greatest opportunity in preventing cancer.
The New York Times followed up with both Dr. Thun and the  chairman of the President's Council Dr. LaSalle D. Leffall Jr.  Here are  their responses (lengthy  excerpt):
Suggesting that the risk is much higher, when there is no  proof, may divert attention from things that are much bigger causes of  cancer, like smoking, Dr. Thun said in an  interview.
“If we could get rid of tobacco, we could get rid of 30  percent of cancer deaths,” he said, adding that poor nutrition, obesity and lack of exercise are also  greater contributors to cancer risk than pollution.
But Dr. Thun said the cancer society shared the panel’s  concerns about people’s exposure to so many chemicals, the lack of  information about chemicals, the vulnerability of children and the  radiation risks from medical imaging tests.
The chairman of the president’s panel, Dr. LaSalle D.  Leffall Jr. of Howard University, said the panel stood by the report.
“This is an evenhanded approach, and an evenhanded report,”  Dr. Leffall said. “We didn’t make statements that should not be made.”
He acknowledged that it was impossible to specify just how  many cancers were environmentally caused, because not enough research  had been done, but he said he was confident that when the research was  done, it would confirm the panel’s assertion that the problem had been  grossly underestimated.

This is an interesting debate that warrants further  discussion.

What do you think?  Share you views by replying in the thread.

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