Margaret Kripke, PhD is professor of immunology and Vivian Smith Chair Emerita at the University of Texas MD Anderson Cancer Center, one of the world’s leading cancer research and treatment institutions. Dr. Kripke was also one of two panelists, along with Dr. LaSalle Leffall of Howard University College of Medicine, who served on the President’s Cancer Panel, which in 2010 produced the report "Reducing Environmental Cancer Risks: What We Can Do Now." The report sparked unprecedented attention, as well as some controversy. Her remarks below come from an interview done for the Collaborative on Health and the Environment.
The President’s Cancer Panel consists of three people who are appointed by the United States President to survey the landscape in cancer research and treatment, and to try to point out what gaps there are and what could be done to accelerate the agenda of reducing cancer. I was appointed in 2003 by George W. Bush, and I served on the panel until 2011. I was nominated to serve in the role of basic scientist; typically the panel has a cancer advocate, a scientist, and a clinician.
We focus on a different topic every year, do an extensive review of the science, and conduct hearings around the country. This topic was extremely controversial. Part of the reason is that environmental carcinogenesis is a topic where there’s a lot of uncertainty. So you have to consider what is going to be the public message and what conclusions could we draw when there are so many things where there’s just not enough information.
The second issue was that this is a very emotional issue for a lot of people, who are concerned about why they got cancer and are convinced that their cancer was caused by something in the environment. I was concerned that we would be diverted from an objective analysis to an emotional issue.
The third issue was that there is a stated figure about how many cancers are caused by environmental agents, and that figure is 6 percent. And it wasn’t clear to me that the President’s Cancer Panel should be focusing on an issue that only affected perhaps 6 percent of cancers. So I was not wildly enthusiastic about this as a topic at the outset.
But one of the reasons I agreed that we should do this is that 6 percent is still 20,000 deaths per year—40,000 people with cancer and 20,000 deaths per year. Those people deserve a voice. A second argument is that this is a subject of huge public interest at the moment. And the third argument is that cancer research has not focused on this area. I’ve been a cancer researcher for my entire career. I go to all the cancer meetings, and hardly ever do you hear anything about environmental carcinogenesis. It’s just not part of the mainstream of cancer research.
I was so naive in terms of my belief that we were being protected from things in our environment. And I was left with a sense that we have very little knowledge about what really is going on in our environment, and we need much more information.
This was an enormously eye-opening experience. I always assumed that if you have something in the workplace that’s regulated, the regulations would be enforced. And this turns out not to be true in all cases. So we have carcinogens in the workplace that are regulated—and the regulations may be very unevenly enforced. I always assumed that if something was a known human carcinogen, that it would be regulated. This is clearly not the case. There are carcinogens in our environment that have been banned in Europe and Canada but still remain unregulated here. Second, I always assumed that before things were put on the market, they would be tested. And that, too, is absolutely not the case. We test very few things for cancer-causing properties. The United States has not regulated much of anything since the 1990s. And the third point is that it’s estimated that there are somewhere around 80,000 man-made chemicals that are currently in our environment, most of which have been put there since the end of World War II. And only around 2 percent or fewer of those have actually been tested for cancer-causing properties. Now, some of them obviously are not candidates for cancer-causing agents, but others are, and we seem to espouse the “reactionary principle,” which is that until something is demonstrated to be harmful, we don’t worry about it; whereas in other places in the world people say, "If we think it’s going to be a problem and there’s uncertainty, we should take a precautionary approach to putting things into the environment."
So our first recommendation is that a precautionary, prevention-oriented approach should replace current reactionary approaches to environmental contaminants in which human harm must be proven before action is taken to reduce or eliminate exposure. It’s the thing that would probably have the most impact on future generations—to quit putting things out there that are untested and then have to bring them back. It was described to us as looking at the end of the pipeline. You have a process—a manufacturing process—that produces a chemical or something that goes into the environment and it comes out of the end of the pipeline and is distributed. To put it back in is very difficult. The remediation of things that are already out in the environment is much more costly than having engineered the process from the beginning to not create toxic by-products and toxic products at the end. In those cases where there is a high potential for risk, we ought to be thinking about that at the beginning, not at the end after it’s already on people’s carpets and on their lawns.
We then included some other recommendations:
- We need to determine the full extent of environmental influences on cancer.
- The nation needs a comprehensive, cohesive policy regarding environmental contaminants and protection of human health (not just cancer).
- Children are at special risk for cancer due to environmental contaminants and should be protected.
- Continued epidemiologic and other environmental cancer research is needed.
- An environmental health paradigm for long-latency disease is needed.
- Existing regulations for environmental contaminants need to be enforced and updated; stronger regulation is needed.
- Radiation exposure from medical sources is underappreciated.
- Medical professionals need to consider occupational and environmental factors when diagnosing patient illness.
- Workers, other populations with known exposures, and the general public require full disclosure of knowledge about environmental cancer risks.
- The military needs to aggressively address the toxic environmental exposures it has caused.
- Safer alternatives to many currently used chemicals are urgently needed.
One of our major conclusions from the report is that children are certainly at greater risk, and the evidence is accumulating that there is an increase in cancer in children for no apparent explainable reason, and also an increase in the number of birth defects in children. I think that’s an extremely important canary in the mine, if you will.
The gratifying part is that there are so many people who are interested in the report, and that people who are interested in environmental issues have been very supportive. On the other hand, there have been a lot of critics of the report —saying that it focuses specifically on environmental causes of cancer and does not include “lifestyle” factors such as tobacco, nutrition, exercise, and so on. But our report two years previously had been on lifestyle factors and their role in cancer causation. We spent half of the report looking at tobacco and half of the report looking at nutrition and exercise, obesity, and those factors in cancer. And number one, of course, is getting rid of tobacco. So we felt we had looked at that issue fairly comprehensively. And I don’t think that this report detracts from other issues. I think people understand multicausality of diseases, and I don’t think that saying there are things in your environment that might be dangerous keeps people from thinking tobacco is bad for you also.
It’s relatively easy to generate a lot of concern and support for curing cancer. We have talked for decades in this country about the war on cancer, the cure for cancer. That has been the focus, and people are energized around that agenda, as they should be. It’s much more difficult to say, "Let’s look at causation of cancer," because the immediate effects are not apparent. It has to come from the American public. It will only change if there is public pressure to do so, because there are a lot of economic interests in the world that are geared toward not having that happen.
There is a separate section in the report that asks, “What can individuals do to reduce their personal risk of cancer?” Because you can’t put out a report like this and not give people some clues as to what they might do. If you work in an industry with chemicals, wash your clothes and take your shoes off before you come into the house—little practical things that people can do, which I think are very important. I participated in an interview and a questioner said, “I’ve never smoked in my life, I’m extremely healthy, I run marathons, there is no one in my family who has ever had cancer, and I have cancer. What about me?” And so to people who say, “Don’t look at environmental causes of cancer because there are other things that are more important,” I say, "What about these people?" People do need to have their concerns addressed, and I hope the report does that.