Around the 1990s, some women who had developed breast cancer began wondering if there were some particular factor causing it. There were regional differences in the incidence of breast cancer. Certain areas were high risk: the Northeast, the San Francisco Bay area (even Sherman ’s Briggs Hill was added—briefly).
Risk factors were upper–income women, older than 50, Jewish, never had children or had first child at a later age, an early age at menarche, menopause at a late age, used hormone-replacement therapy, with (poor) diets rich in fats, and a family history of breast cancer..
Those were known high-risk factors. However, they could not be used to predict which women would get breast cancer nor could they be used for prevention. To those high-risk factors, alarmists added environmental pollution, with air-pollution still another factor (but small if at all).
Epidemiologist Geoffrey C. Kabat’s new book, Hyping Health Risks, Environmental Hazards in Daily Life and the Science of Epidemiology, tells the story of breast cancer in Long Island in fine, full, and meticulous detail. To it we now turn, following a discussion of this unusual book in our November 26 column.
Long Island had been growing rapidly in population. There was concern about environmental factors and a possible link to cancer. Long Island was an important agricultural region in the 1950s, and there was concern about DDT, other pesticides, and their possible link to cancer. In the 1960s there were additional concerns: landfills, incinerators, industrial sites, and heavy auto and air traffic. There were emissions of radionuclides from the Brookhaven National Laboratories’ nuclear reactor.
Breast-cancer activists took surveys in their neighborhoods and found “clusters” of breast cancer, which government was not explaining or investigating. Activists formed organizations. One, called “One In Nine,” wrongly gave the impression that women’s odds of getting breast cancer were as high as one in nine. But those odds were applicable to 80-year-olds and older who had not developed breast cancer. The odds of younger women’s getting breast cancer were smaller and varied with age.
Several towns had their own breast-cancer organizations. Activists founded the Long Island Breast Cancer Network. The women, well-informed, highly vocal, politically effective, joined with prominent scientists who were concerned with breast cancer. Together they demanded that government do something to find the cause. They lobbied politicians for funds for research. Out of their efforts came a congressional bill for a breast-cancer study on Long Island .
The study, mandated by Public Law 103-43, was passed in 1993. The law brought together science and politics. It surprisingly specified the type of study to be done—“a case-control study to assess biological markers of environmental and other potential risk factors contributing to the incidence of breast cancer” on Long Island.
The Law called for evaluation of exposure by monitoring and cumulative estimating of contaminated drinking water, indoor and outdoor air pollution, emissions from aircraft, electromagnetic fields, pesticides, hazardous waste, and other “appropriate” factors.
The law called for scientists to find “biological markers,” not the same thing as causes. The activists were looking for causes. Professor Kabat doubts that the scientists and politicians-activists ever actually understood the study in the same way. The study called for a high-powered “geographic information system,” which required long-run Long Island data on air, water, soil, and food, which were not available. (Ten years later, the original geographic information system was still being developed.) The study would give them not data but “biological markers,” which were not designed to elicit the cause—which the activists never quite understood.
Still another problem was that the law specified two counties, Schoharie in New York State and Tolland in Connecticut —to increase the political support for the bill in Congress. The latest available data showed those two counties as having the highest breast-cancer mortality in their states. But it was a mistake. Unfortunately, both counties have very small populations—too small to be usable for mortality purposes. The following up-to-date data showed Schoharie County as having fewer than a dozen breast-cancer cases, the lowest incidence in all 68 New York State counties.
Was the problem the result of combustion products (burning or charcoal-broiled) or organochlorine compounds including DDT and PCBs? Neither. And the togetherness of scientists and activists did not work. In fact, neither side quite understood the other side. That outcome does not preclude the possibility that there may be some environmental factor involved, but the contribution, according to Dr. Kabat, is likely to be small. Research could look into whether other factors might be involved: early events and exposures during and after puberty.
“This study is the envy of the nation. Every women’s group wants it, and Long Island has it,” remarked the lead researcher of the study.
But, concludes Professor Kabat, it was “a naïve expectation” that this one set of studies was going to deliver a break-through. “It was as if, in the flush of launching the study, both NCI [National Cancer Institute] and the researchers succumbed to the naïve expectations of the activists.”
By Natalie Sirkin