Choosing One's Battles
Secret History of the War on Cancer. Devra Davis. xviii + 505 pp. Basic Books, 2007. $27.95.
We are all born innocent. In the United States, we grow up expecting to be kept safe; the idea that known carcinogens might be tolerated in our homes, our workplaces or the products we use doesn't occur to us. If the issue crosses our minds at all, we probably assume that the government arranges for expert scientists to objectively evaluate the evidence regarding suspect substances and then issues regulations banning those that are found to cause cancer. Watchdog agencies are on the job, so we have nothing to fear—or so we would like to think.
Americans who haven't already been disabused of this notion will have their eyes opened by Devra Davis's well-written new book, Secret History of the War on Cancer. Davis, a professor of epidemiology at the University of Pittsburgh and a veteran of many battles to protect public health and the environment, has participated at the highest scientific level in an arena in which power politics twists the science, industry pays so-called experts to make people believe that its carcinogenic products are actually safe, and business interests employ an array of other defensive strategies. She writes as a keen observer of this interesting and daunting world, where our lives hang in the balance, along with the health of the environment and of future generations.
Participants in the "war on cancer" that President Richard M. Nixon declared in 1971 have fought "the wrong battles," according to Davis, by focusing on diagnosis and treatment of illness rather than its preventable causes. She maintains that since 1971 at least 1.5 million Americans have died needlessly because of their government's failure to act on what has long been known about social and environmental causes of cancer. Her book is an insightful critique of our society's lack of progress in controlling those causes. In it she tracks the forces that have stymied such progress from the 1930s to the present.
By the late 1930s, much had already been learned about carcinogens through animal experiments and reports of certain types of cancer in workers exposed to benzene, chromates, tars, coal-tar dye intermediates, radiation and asbestos. But not until the 1970s, during the Carter administration, did the U.S. government finally appear to get serious about investigating cancer-causing substances: The National Cancer Institute set up programs evaluating the effects of tobacco and of some industrial chemicals; the government began testing chemicals in its own laboratory under the National Toxicology Program; and Congress passed the Toxic Substances Control Act. But unfortunately, as soon as the Reagan administration took over, those programs began to be undermined. Davis explores the myriad reasons so little headway has been made over the past 75 years, and by digging into history she reveals a great deal.
For example, she describes how the American Society for the Control of Cancer (ASCC, later renamed the American Cancer Society) was formed in 1913 to spread the word to physicians that cervical cancer could be discerned visually and to convince women that they should let themselves be examined. George Papanicolaou discovered in 1928 that the cancer could be detected more reliably by swabbing a few cervical cells, but as Davis relates, widespread use of the Pap smear as a cheap, effective method of screening for cervical cancer was delayed for decades by organized medicine, because doctors were apoplectic over the notion that the smears could be analyzed competently by people who weren't physicians.
In the late 1930s, the ASCC organized the Women's Field Army, recruiting 2 million volunteers who went door-to-door informing women about the need to be examined by doctors to find cancer early. After the war, leading industrialists donated large sums to the American Cancer Society and took over its board of directors. As a consequence, the Society focused on diagnosing and treating cancer but did not address the need to control or ban products already known to cause the disease, such as asbestos, benzene and tobacco.
By the 1930s, German scientists had shown that the death rate from lung cancer was higher in smokers than in nonsmokers and that those who smoked more heavily had a higher death rate. When similar work was reported in Britain and the United States in the early 1950s, the tobacco industry decided to set up its own research council to create doubt about the dangers of smoking while giving the appearance of adding to scientific knowledge about smoking and health.
Clarence Cook Little, who had formerly led the ASCC and the U.S. National Cancer Institute, was hired to direct the Scientific Advisory Board of the Tobacco Industry Research Council in 1954. Big Tobacco went on to "write the book" on presenting experts to question the evidence that a product causes disease, and the industry continues to use the strategy today: R. J. Reynolds Tobacco Company provides funding for the journal Regulatory Toxicology and Pharmacology, which is edited by tobacco industry consultant Gio Gori.
Davis intersperses her accounts of battles in the political, regulatory, legal and public-information arenas with lucid explanations of the uses and limitations of epidemiology (the statistical study of how, when and where diseases occur and what the risk factors for them are). She describes how the case-control study in epidemiology—a retrospective method of research that was largely developed in the second half of the 20th century—came under attack by opponents of regulation. Every epidemiology study ever done has had at least some data limitations, she points out, and the tobacco and chemical industries have made the most of that fact, hiring eminent scientists to find technical grounds for relentlessly criticizing reports indicating that certain products and pollutants cause cancer. "More research is needed," they always say, an objection that has the advantage of sounding scientific.
Davis quotes Sir Bradford Hill, one of the founders of modern epidemiology, who was renowned for elucidating criteria for evaluating the strength of epidemiology studies. He cautioned against concluding that "no [statistically] significant difference" equates to "no difference" when one is interpreting data on whether a risk factor causes disease. "Like fire," Hill said, "the chi square test [of significance] is an excellent servant and a bad master." He also gave this warning:
All scientific work is incomplete—whether it be observational or experimental. All scientific work is liable to be upset or modified by advancing knowledge. That does not confer upon us a freedom to ignore the knowledge we already have, or to postpone the action that it appears to demand at a given time.
Davis describes the tragic history of asbestos and the hiring of Richard Doll, Hill's coauthor of historic studies of cancer in smokers, as a consultant to the asbestos industry and to other industries fighting regulation and liability. After citing a 1984 Canadian report on asbestos that characterizes human tragedy as "the harshest of schoolmasters," Davis notes that Canada and other asbestos-mining countries do not seem to have learned much from that schoolmaster: They are still exporting large amounts of asbestos to poor countries in Asia (even as dozens of countries have banned asbestos).
Late in the book Davis touches on such topics as the developing research on potential cancer risks from Ritalin and from cell-phone use. She also relates in some detail the astonishing story of the artificial sweetener aspartame.
In 1977, the U.S. Food and Drug Administration asked for a grand-jury investigation of aspartame's manufacturer, G. D. Searle and Company, for knowingly misrepresenting findings, concealing material facts and making false statements to the government. Searle was accused of having suppressed the findings of studies it had sponsored that had shown that aspartame causes severe epileptic seizures in monkeys. The company then named Donald Rumsfeld as its chief operating officer (just after his first stint as Secretary of Defense). Also, a law firm working for Searle hired the attorney who had been in charge of prosecuting the case against the company before the grand jury, and later also hired the prosecutor who replaced him.
Experimental work submitted by Searle in support of aspartame safety was deemed invalid by every scientific group that examined it. An FDA review panel recommended against approval of aspartame in 1980, the year Ronald Reagan was elected to replace President Jimmy Carter. Rumsfeld told his cohorts he would "call in his markers" with the FDA, and sure enough, just five months after Reagan's inauguration, the new FDA commissioner, ignoring the recommendations of yet another review panel, approved aspartame for use in a number of products.
A 1996 survey by Ralph G. Walton reviewing 165 studies of aspartame published over the preceding 20 years revealed that no study with industry ties found aspartame to be harmful; the only studies to raise concerns about its safety were those conducted by independent scientists. An independent experimental study by the European Ramazzini Foundation, whose findings were published in 2005 and 2006 with Morando Soffritti as lead author, found an excess of leukemias, lymphomas and other tumors in Sprague-Dawley rats that had consumed a daily dose of aspartame well under the 50 milligrams per kilogram that the United States considers allowable in humans.
Reading one shocking story after another about industry manipulations could become dispiriting, so it is fortunate that The Secret History of the War on Cancer is peppered with anecdotes about the work and experiences of scientists, nurses, doctors, workers and cancer victims, who have all made progress in the face of great obstacles. For example, Davis contrasts the powerful opposition faced by environmental cancer researcher Wilhelm Hueper with the career of lead industry consultant Robert Kehoe, illustrating struggles that were largely invisible to the general public in the decades before the era of regulation began in the 1970s.
As Davis points out, "highly profitable industries have no incentive to ask whether the products on which they depend may have adverse consequences." No public information is available about the toxicity of three-quarters of the chemicals in high-volume use today. To make matters worse, a 1993 Supreme Court decision (Daubert v. Merrell Dow) has led to a trend for courts to limit the scientific evidence that can be presented to juries to establish that an exposure has caused harm. How can causation be proved when there are no epidemiology studies, and when judges have excluded experimental studies and case reports as irrelevant? Davis shows that reducing the liability risk of companies that are selling toxic products is an invitation to abuse.
Although this book focuses on carcinogenic substances, the outcome is the same whenever public health and environmental protection conflict with an established means of making vast profits. A similar book on global warming will be written someday, describing the same sorts of failures to take preventive steps. Young scientists can learn a great deal from what Davis shares about her personal experiences and those of her fellow public-interest scientists and activists.
It is disheartening to read of the obstacles to progress in cancer prevention, but Davis performs a valuable service in exposing sordid failures to protect the population from known cancer hazards. Her book lays the groundwork for a fundamentally different approach, that of taking precautions to reduce hazards in the workplace and the environment.