Cancer

To the Editors:

While I appreciate Dr. P.B. Medawar’s generally favorable review of my book, The Cancer Connection: And What We Can Do About It (NYR, June 9), I must take issue with several of his contentions; if unchallenged, they are apt to lead us still further astray in the search for a more productive national cancer policy.

Dr. Medawar questions my claim that cancer is largely a preventable disease. In the words of his review, “I think this case is overstated.” I think not. A quick survey of blue-collar job categories suggests the preventable nature of the problem: Rubber workers exposed to benzene and other known cancer-causing compounds are dying of cancer of the stomach, cancer of the prostate, and leukemia and other cancers at rates ranging from 50 percent to 300 percent greater than in the general population; at the same time, hundreds of thousands of construction and insulation workers are exposed to asbestos fibers—notoriously carcinogenic—and are dying from lung cancer at a rate more than seven times normal; steelworkers, printers, uranium miners, plastics workers, and chemists too are among those on a rapidly lengthening list of employees dying at excessive rates from cancers linked to known occupational carcinogens. This plethora of occupational cancer epidemics, coupled with similar evidence emerging from non-occupational studies, lends grisly substance to the claim that as many as 90 percent of all human cancers are attributable to environmental carcinogens. (Dr. Medawar is apparently more comfortable with a figure of 80 percent.) By definition, these cancers are theoretically preventable by altering our relationship with our environment. As a practical matter, of course, it would be impossible to eliminate all environmental carcinogens; but when we separate out what is both possible and practical, we are left with a realistically achievable goal of reducing our national cancer incidence by 30 percent by the 2000 or 2010.^*

Notwithstanding its inherent promise, cancer prevention remains far down on the national agenda. To my knowledge, virtually no attention has been given to the urgent task of establishing a comprehensive national carcinogens policy, designed to systematically reduce human exposure to known and suspected carcinogens.

I regret that Dr. Medawar is in error when he writes that the federal Occupational Safety and Health Administration (OSHA) holds to the axiom that “there is no known ‘safe’ level of exposure to a cancer-causing agent.” If only it were so! OSHA, like other federal agencies, has not yet abandoned the discredited notion that there are “safe” levels of exposure to some carcinogens.

As for my being “a little unworldly in reproaching OSHA for aiming at ‘compromise’ levels of exposure for political reasons,” let’s make no mistake about what is at issue here: human lives by the hundreds and by the thousands. Experience teaches us that what industry asserts as essential to corporate survival is all too often revealed as just so much bunk. The du Pont Company recently admitted that 339 of its 2,000 workers exposed to beta-Naphthylamine (BNA) during the years 1919-1955 fell victim to bladder cancer. Although du Pont knew BNA was an incredibly potent human carcinogen as early as 1938, the company didn’t eliminate the substance from its dyestuffs operations until 1955. Not surprisingly, du Pont has survived since without BNA. Similarly, plastics manufacturers publicly predicted industrial doom if OSHA went too far in controlling vinyl chloride, the wonder gas implicated in an epidemic of liver and brain cancer among exposed workers. When, in this one instance, OSHA got tough and adopted a standard cutting maximum exposures to roughly 1/500th of their previous levels, the industry managed to survive. Indeed, it continues to flourish. Those of us who have the good fortune to be far removed from the front line hazards of industrial production have a special responsibility to be wary of compromises insofar as cancer-causing substances are concerned. In regulating carcinogens, it is not enough to compromise the difference between human health on the one hand and claims of corporate jeopardy on the other; a blind retreat to the sacred “middle ground” is apt to be over the dead bodies of many Americans.

Concerning Dr. Medawar’s guess that worldwide cancer research has consumed hundreds of millions of dollars—not billions, as I wrote—the fact is that the United States effort alone has exceeded $3 billion since 1970. The point here is not to quibble over the amount of aggregate research expenditures, but rather to ask whether these expenditures are allocated in a manner to most effectively combat the cancer peril. Clearly, they are not. Nearly all funds appropriated to the National Cancer Institute are directed toward the development of therapies and the search for the illusive cancer cures. The money continues to follow the path of least political resistance, and cancer prevention goes begging. There should be no wonder about this. Enormous political courage is required to take on du Pont, B.F. Goodrich, and the entire petrochemical industry, not to mention the tobacco lobby, the food additives producers, the pesticides manufacturers, and all the rest. In the final analysis, we must recognize the Cancer Connection for what it is: not merely a chemical and biological phenomenon, but a national tragedy rooted in our social, political, and economic systems as well.

Larry Agran

Irvine, California

Peter Medawar replies:

I thought Larry Agran’s The Cancer Connection: And What We Can Do About It a rather good book and gave it a favorable review, but I cannot review his letter of complaint anything like so favorably. Mr. Agran, I should say if I were reviewing his letter, is one of those tiresome authors who is satisfied with nothing less than unqualified praise and complete acquiescence in his opinions—and he is all the more tiresome because the points of difference between us are not really very profound. Whether billions of dollars or merely hundreds of millions of dollars are spent on cancer research, it is by any scale of reckoning an extremely large sum and one for which the citizenry can reasonably expect a very tangible return.

Then again, we should not really be at loggerheads about whether 90 percent or only 80 percent of all cancers are environmentally caused. It is in any event a disturbingly high percentage. No: what I thought overstated in Agran’s case was his implication that if 90 percent of cancers are environmentally caused then 90 percent are preventable. There is indeed a biological sense in which all cancers are environmentally caused and unless there really is such a thing as a “spontaneous” cancer, which I doubt, then all cancers are caused by influences external to the cell that responds to them by a malignant transformation. Yet such cancers may easily not be preventable.

As to OSHA, Agran writes too much like an attorney in a “B” movie for my taste.

I am sorry that it should be so, but in real life compromise is almost always necessary. If life and death were the only credit and debit entries in the balance sheet that spells out the cost to human well-being of dangerous chemicals or building materials then perhaps we should be justified in taking a completely uncompromising stand: justified, that is to say, in repudiating altogether the notion of compromise and insisting unconditionally on the abolition of automobiles, asbestos and all fuels of which the combustion produces hydrocarbon smokes. But these ambitions are impractical, for we have also to consider people’s jobs, their means of transport to and from them, and the cost and thermal efficiency of their housing, etc. Utopian social engineering is less effective in the long run than identifying and ascertaining the cost, in terms of over-all human life and welfare, of the use of smoky fuels, food additives or rogue industrial chemicals which for any good reason come under suspicion. Larry Agran’s book is a most important step in the direction of achieving these ostensibly lesser but in reality more realistic ambitions and I take this opportunity of praising him for it once again.