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The Secret History of
the War on Cancer

Excerpt

Chapter 2 - Natural and Other Experiments

"Tragic sins become moral failures
only if we should have known
better from the outset."
— Jared Diamond

Late in 1936, Time magazine reported on the remarkable four-week journey of Maud Slye, a pathologist at the University of Chicago. It was her first vacation in twenty-six years. Though largely unknown today, Slye is sometimes referred to within her specialty as America’s Marie Curie. She devised an innovative program showing that mice could be bred at will to have cancer or not. Her work remains a cornerstone of cancer research to this day.

Slye spent half of the month traveling. To leave her mostly academic (and mostly white) enclave of Hyde Park on Chicago’s South Side, she probably scheduled a Checker cab. The uniformed driver would have taken her along windswept Lake Shore Drive, right next to Lake Michigan, to Union Station downtown. At the station she must have boarded the Empire State Express and spent two nights in one of the sleepers. White-gloved black waiters served her meals in a well-appointed, walnut-paneled dining car. Some forty hours later, she would have arrived in Manhattan’s central train depot, the cavernous, marble-floored Penn Station. Another cab would have taken her to a passenger ship docked behind the pink granite facades of Chelsea Pier in New York Harbor on the west side of Manhattan. The champion black athlete Jesse Owens and the American Olympic team had set sail from the same place just a month before, en route to the Olympics in Berlin, Germany. At those games, the racist Nazis were appalled at Owens’ success. He set records in all but one of his events while becoming the first person in history to win four gold metals in a single Olympics. Twenty years before that, my immigrant grandparents were ferried from this same pier to Ellis Island, where they stood in lines to be screened to see if they were fit to enter the country.

If Slye had sailed on the 75,000-ton Queen Mary’s first voyage from America, she would have landed a week later at Southhampton, in the south of England, and taken another ship to the European Continent. More likely, she boarded one of the older, slower ships that took ten days and landed in the north of Belgium at Antwerp, on the right bank of the River Scheldt by the Westerschelde. From there, Slye would have boarded yet another train for her destination—the country’s capital city, Brussels.

The Time story made it clear that Slye did not make this journey alone. More than two hundred of the world’s top cancer scientists convened in Brussels that summer to attend the Second International Congress of Scientific and Social Campaign Against Cancer.  The meeting had the makings of a veritable Manhattan Project on cancer: the best minds available, poised to create something astonishing and new.  The great experimentalist Isaac Berenblum later remembered it as “the most momentous cancer congress ever held.”1 The scientists sailed from Latin America, America or Japan, a journey that could have taken close to two weeks, or took sleeper-car trains from Russia and Europe. With the world clearly on the brink of war, such a trip required considerable courage, as well as a strong stomach. At least one of the participants (Wilhelm Hueper, whom we will meet in Chapter 4) had survived poison gas attacks in the Great War; no doubt several others had had similar experiences. They kept no secrets—government or industrial—but ironically this historic gathering has itself remained nearly secret for more than seventy years. Many of your late relatives and mine might still be with us if the things these eminent women and men of science knew about the causes of cancer in 1936 had entered mainstream medical practice.

But they didn’t. Something mysterious happened over the course of the twentieth century. At that meeting in Brussels the accomplishments of several centuries of cancer research flashed onto the scene, ready to coalesce into a substantial and coherent body of scientific understanding about the environmental causes of cancer. Instead, many of these accomplishments were forgotten, their message ignored. Much knowledge that really mattered ended up in that dusty section of the library reserved for books that are never read and papers that are never cited. Today, we’re locked in ferocious debates about matters that scientists thought they had solved more than three generations ago. What kinds of evidence tell us the causes of cancer that we can do something about? What passes for scientific proof, while ultimately founded in methods and measures, is not immune to changing political and economic forces.

I first learned of the Second International Congress of Scientific and Social Campaign Against Cancer from a brief reference to it in a memoir by Berenblum. It turned out that the proceedings—the collected papers presented there—were not to be found in any medical library in either Pittsburgh or Washington, D.C. My friend Carol Conners, the indefatigable reference librarian at Teton County Public Library in Wyoming, assured me that if a single copy existed anywhere in the world, she would find it. She did. I wasn’t quite sure what to expect when I formally requested the three-volume set from the library in Belgium where it was stored. I thought I would learn how naive the world of cancer research had once been.

But after the books arrived, I spent a sleepless night fascinated by the sophisticated drawings and advanced research techniques that were employed to unravel the causes of cancer before I was born. The next morning, I scanned some of the most critical reports and put them on a web site for my colleagues that you now can find on this book’s web site. I knew they would be just as stunned as I was to see how much was known about the social and environmental causes of cancer before World War II, seventy years ago.

Many of the texts were written in several languages, English, Spanish, French, and German, all presumed to be understood by the multilingual scientific crowd. One speaker, Clarence C. Little (whom we will also meet later), then famous for creating ways to study the inheritance of cancer in mice, argued that animal studies proved that most cancer arose from inherited defects. But at this conference, the view that cancer was dictated by our genes was in the clear minority.

William Cramer of London’s Imperial Cancer Research Fund carefully examined patterns of cancer in people over about a century. He was able to do this because at the time, the British had been keeping records of deaths and illness for more than three hundred years. Cramer noted that much of the recorded increase in cancer was nothing other than better record keeping and people living longer. He went on to present techniques for evaluating these patterns that took these facts into account. The numbers of cancer cases had almost doubled since the turn of the century. Taking into account the fact that more people were alive and older, cancer had become about one-third more common than at the beginning of the twentieth century.

Cramer also pointed to other proof of the modern growth in cancer, noting a profoundly simple and important observation that has since been repeatedly confirmed. He thought it important to look at what happens in what he called “uniovular” twins—more commonly known as “identical” twins, those that arise when a single fertilized egg splits into two developing embryos. In 1936, he already had determined that in most of these genetically identical pairs, if one develops cancer, the other does not. Cramer concluded that “cancer as a disease is not inherited.” He urged that patterns of cancer—especially those of the workplace—should be tracked in order to learn how to control and reduce the disease.

Cramer understood that human cancers were the result of past exposures, some 20 or more years ago. If one wanted to make progress against cancer it would be important to rely on experimental research with animals. Animal tests provide an important way to learn whether chemical and physical agencies which produce cancer in animals also produce cancer in man. Cramer noted that cancer often develops in both rodents and humans in the same tissues. The time between exposure to a chemical and the time when a tumor shows up varies greatly, occurring within a year in rodents and after decades in humans. Yet this period of latency is remarkably similar if expressed in fractions of the usual span of life in each case. Cramer argued that cancer is one of the few diseases in which the experimental production in animals closely simulates the disease in man. He allowed that cancer in humans may, in fact, be considered an experiment carried out by people on themselves.

The three volumes from this congress included surprisingly comprehensive laboratory and clinical reports showing that many widely used agents at that time were known to be cancerous for humans, including ionizing and solar radiation, arsenic, benzene, asbestos, synthetic dyes and hormones. Angel Honorio Roffo, the founding director of the Institute of Experimental Medicine in Buenos Aires, Argentina, described experiments showing that both invisible forms of radiation—ultraviolet and x-ray—could produce cancers in animals.  He was one of several experts at the time to show that these tumors could be surgically cut out from one animal and made to grow in another, a method of tumor transplantation still in use today. Roffo’s work referenced even earlier experiments by Andre Clunet, who had produced sarcomas in rats in 1910, and clinical reports by Bruno Bloch from 1923 finding that radiation induced cancer in animals and in workers.

Roffo’s own studies of workers showed that those with the greatest amount of time spent outdoors had the greatest vulnerability to skin cancer. His paper was accompanied by exquisitely detailed drawings of sprawling tumors growing from the heads, eyes, ears, and necks of rats following months of solar or x-ray treatment. He also reported that combining some hydrocarbons with either sunlight or radiation produced much worse cancer damage than any one of these exposures alone. He advised avoiding radiation and sunlight, and reducing exposures to hydrocarbons. These are observations that the modern world didn’t begin to take seriously until the 1980s. 

Roffo was one of many experts to issue a strong statement against the fashionable view that a tanned skin signaled good health. At a time when movie stars and suntanned cowboys were seen as glamour figures, he concluded by “protesting strongly against excessive sunbathing which exposes the skin to intensive irradiations from the sun, placing individuals, victims of a ridiculous fashion, into a particularly dangerous state of receptivity to the development of skin cancer.”

I had expected to find amusing errors and preposterous assumptions in the conference volumes, but I didn’t. The papers did not depict the dark ages of cancer research but rather an exhilarating time of lively and important work that seems to have come and gone like a comet. A review of carcinogenic chemical compounds by the noted researchers J.W. Cook and Edmund L. Kennaway and others with London’s Royal Cancer Hospital reported that more than thirty different studies had found that regular exposure to the hormone estrogen produced mammary (breast) tumors in male rodents. The National Toxicology Program of the U.S. government did not formally list both estrogen and ultraviolet (sun) light as definite causes of human cancer until 2002.

How did these scientists decide what was a cause of cancer in 1936?  They combined autopsies with medical, personal and workplace histories of people who had come down with cancer. They reasoned that if they found tars and soots in the lungs of those who had worked in mining and showed that these same things caused tumors when placed on the skin or into the lungs of animals, that was sufficient to deem these gooey residues a cause of cancer that should be controlled. Their animal work was quite sophisticated in today’s terms, extending from complex laboratory studies of rats, mice, rabbits, monkeys, dogs and cats to various physical and chemical agents that left clear marks of cancer.

In many ways the 1936 congress was the culmination of centuries, even millennia, of earlier work. The long view of cancer history is a tale of intrigue, courage and extraordinary dedication. It’s a story of physician scientists who were also keen observers of everyday life and who expressed a rigorous urgency to learn, no matter where their inquiries took them. Many of the basic causes of cancer were identified hundreds of years ago. Mining, painting, smelting, forging, distilling, curing, smoking, grinding, and cleaning were portrayed in literature and excellent medical accounts—some dating from the Middle Ages—as risky enterprises. These observations were confirmed in the first half of the twentieth century by experimental studies of rodents, rabbits and other small mammals. Much of this knowledge deserves to be central to medical education and practice. But modern cancer medicine has a collective amnesia about its own history.

Reprinted with permission © Basic Books, 2007.

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