Where we stand in the fight to conquer cancer
Some of the world’s leading authorities give their opinions on such vital questions as: What causes it? How can you guard against it? Can science find a cure? How soon? Is anyone immune?
A MACLEAN'S PANEL DISCUSSION
Are we making headway in the fight against cancer? For an unusually authoritative answer to this question. Maclean's Magazine recently took advantage of a rare opportunity to assemble a panel of eight distinguished cancer authorities. For three hours, assistant editor Sidney Katz put questions to the following experts:
The answers given by these scientists to dozens of questions were taken down by a tape recorder. Managing editor Pierre Herton acted as moderator for the discussion. It was possible to assemhie so many brilliant cancerologists at one time because they were attending a conference sponsored by the National Cancer Institute of Canada at a Georgian Bay hotel. This year, the National Cancer Institute of Canada will spend $750,000 on cancer research: sixty percent of the funds will come from the Canadian Cancer Society, the balance from federal and provincial governments.
CANADA: Dr. A. W. Ham, research adviser, National Cancer Institute: professor of anatomy, University of Toronto. Dr. C. P. I.ebloud, research adviser. National Cancer Institute; professor of anatomy, McGill.
ENG 1.AND: Dr. A. Haddow, Royal Cancer Hospital. London.
FRANCE: Dr. A. I.acassagne, Pasteur Institute, Paris.
ISRAEL: Dr. I. Berenblum, Weizmann Institute of Science.
UNITED STATES: Dr. C. Chester Stock, Sloan-Kettering Institute for Cancer Research, New York. Dr. Henry S. Kaplan, Stanford University School of Medicine,
San Francisco. Dr. W. U. Gardner, Yale University.
This was the question: Will we find a cure for cancer—and when?\
U. S. A.
In the whole field of medicine, the most painstaking and intensive program of research is directed toward finding the causes and cures of cancer. This is because cancer is the most dreaded of all diseases. The situation in Canada is not unlike that existing in other nations. Last year, cancer killed fifty-five men, women and children a day or a total of twenty thousand deaths for the year.
As a cause of death it is second only to diseases of the heart and blood vessels which kill 45,000 Canadians a year. Every person is a potential victim. Last year, 3,000 cancer casualties were under fifty; 300 were children under ten. Cancer killed more children between the ages of five and fourteen than any other disease.
On the whole, eminent members of the Maclean's panel retlected an air of sober optimism about the fight against cancer. Most of the current research projects were long term, although, as Dr. Haddow of England observed, “it's entirely possible that a cure will be found tomorrow.” New “wonder drugs” are being discovered. Some of them can keep some victims of leukemia (cancer of the blood) alive for two years or more; they once died in a tew weeks. The hottest clue in cancer research—supported by numerous laboratory experiments—is that the disease may be caused by a virus. Poliomyelitis is also caused by a virus and it has been conquered by the Salk vaccine. Interesting relationships are being discovered between hormones and / cancer: hormone treatments are helping both male and female cancer patients.
On the negative side, the scientists warned that the fight against cancer is being held up by a lack of trained research workers; that the practice of adding coloring and preservative agents to food without fully testing them can lead to cancer; that ordinary luminous wrist watches and car panels may be hazardous; that doctors may sometimes endanger the lives of patients by taking too long to detect cancer.
Here is an edited account of the discussion between the Maclean’s editors and the eight cancer specialists.
When will we find a cure for cancer?
Haddow: Em optimistic. I have no doubt that eventually we will conquer cancer. But, since most of our research programs are long range and well thought out, I'd hate to put an exact time on it.
Katz: Would you be surprised if an effective cure was discovered within a year?
Haddow: It’s improbable, but it’s also entirely possible that a major discovery might be made tomorrow. That’s one of the things that makes cancer research so exciting.
Stock: You can’t predict the events to come in science. For example, the drug firms worked a long time trying to develop a serum for pneumonia. They were taken by surprise when the sulpha drugs were discovered. I don’t think we can predict when w'e'U have a wonder drug against cancer, although I think it will definitely come and can come quickly. But personally I think it will take a while.
Berenblum: I wonder whether it’s kind to the public to make a prediction. People might get the idea that we practically have a cure in our lap. 1 think it would be safer to be pessimistic about an early discovery and be pleasantly surprised if it happens.
Lacassagne: To me, it doesn’t seem possible that any one discovery will solve all the problems of cancer. Different cancers seem to develop differently. Different countries may succeed in finding a cure for one special cancer and not the others. I think we should be thinking in terms of drugs that can prevent cancer before it reaches an acute stage.
Ham: 1 think it will take a long time and come gradually, step by step. On the other hand, I wouldn’t be terribly surprised if I woke up tomorrow and found that someone had pretty well solved the entire problem.
Gardner: 1 think it's dangerous to assign a time that a cure for cancer will be discovered. As a matter of fact, at present there are already many types of cancer that we can control very nicely—cancer of the skin and other local cancers, for example.
Kaplan: That is a question which, as phrased, is far too broad to be answered. Dr. Lacassagne has referred to the fact that cancer has many facets. There is the question of causation or the actual formation of the tumor cells, and then there is the behavior of the tumor after it is there, and finally there is the possibility of cure.
Leblond: It may be that the major discovery has already been made but that we don't yet know how to apply it. For instance, when radiology was discovered we had no idea that it would be useful in treating cancer.
What’s holding up cancer research?
Gardner: There’s a bottleneck, but it’s not money; it’s manpower. There are simply not enough young men with medical degrees and scientific training to do research. At least that’s the situation in the United States.
Katz: I wonder if Dr. Leblond or Dr. Ham could comment on the situation in Canada.
Ham: We’re suffering from the same lack of trained personnel. To conquer the cancer problem, we need a lot of highly intelligent scientists working on specific projects for a long time. The big handicap now is that a lot of the research money is given only on a yearly basis. You can’t attract good men for just a year. The National Cancer Institute of Canada is having some success in trying to change this.
Leblond: There’s also the question of compensation. I've had some topnotch researchers in my department at the university earning between $6,000 and $7,000 a year at cancer work. These same men can make up to $30,000 in private practice as surgeons and radiologists. 1 think people in cancer should be paid more than those engaged in other fields of research. In most fields of biochemistry or anatomy, you can finish a piece of work in six months or a year and gain recognition by publishing a paper. You can’t do this in cancer—it can easily take four or five years to gather material for even a small paper.
Berenblum: A short-term grant is likely to lead to the study of trivial problems because only a trivial problem can be finished in a year. The most important problems are usually long-term projects. I think Canada and other countries are beginning to realize this.
Here are the compelling answers of eight of the world's top experts
U. S. A.
U. S. A.
Does a virus cause cancer?
In recent months there has been a great deal of speculation in scientific circles that cancer may be caused by a virus or viruses. The panel took a few minutes to explain what a virus is. It's smaller than the smallest bacteria. Unlike a bacteria, a virus is not a complete cell. It cannot reproduce independently. However, once it gets into a cell the power of life is conferred on the virus and it can reproduce itself. Viruses are the cause of such diseases as measles, influenza and poliomyelitis. A virus is “filterable”—if you prepare a liquid extract from the brain of a cancerous fowl and pass it through a super-fine filter the virus will come out the other side.
Scientists have taken filtered extracts from leukemic chickens, and by injection have given leukemia to other chickens. The same has been done with other animals. By preparing a vaccine from these filtered extracts, it has been possible to give mice a temporary immunity to leukemia. Such experiments have so impressed Dr. Wendell M. Stanley of the University of California, who won a Nobel Prize for his work with viruses, that he recently declared: “The fact that viruses have not yet been seriously implicated in human cancer does not mean that they are not there and that they are not of importance. I believe that the time has come when we should assume that viruses are responsible for most, if not all, kinds of cancer, including cancer in man, and design and execute our experiments accordingly.”
Kaplan: I don't think it's fair to talk about the cancer virus. There are many viruses known and more being discovered every week. It s probable that there are thousands of kinds of viruses— perhaps hundreds in cancer alone.
Berenblunt: The problem could be simplified by asking two questions: First, can viruses produce cancer? The answer is undoubtedly yes. There are quite a number of tumors that can be propagated by viruses. Second, “Are all tumors caused by viruses or just some tumors?” The answer is, there is no answer. Cancer researchers ave disagreed on this for fifty years.
Katz: In recent experiments mice injected with filtered leukemia extracts developed three different forms of cancer. Is it possible that the same virus is responsible for different forms of cancer?
Stock: We don’t know that only one virus is present in the extract.
Kaplan: There's some reason to believe that different cancer viruses travel together.
Katz: It has been suggested that a cancer virus may enter the cells of the body and lie dormant there for years. A tumor develops only when something triggers the growth—old age or persistent irritation or a carcinogenic chemical.
Lacassagnc: That's possible—but I'd like to get back to the idea that it's unlikely that a single factor causes a cancer to develop. It could be caused by the virus—but then there are other conditions that must be present too, such as the person’s hormone activity, the place he works and lives, smoking and so on. The problem mustn't be simplified. My view is that a cancer is the result of a lot of things acting in combination with each other.
Are hormones related to cancer?
Ham: They evidently are in some cases. Female cancer of the breast is an example. The breast does not start developing until puberty. This development is due to the fact that female sex hormones (from the ovaries and possibly the adrenal and hypophysis glands) have appeared in the blood stream. If cancer develops in the breast the cancer cells are evidently also dependent on these hormones. Hence if the glands that produce these hormones are removed the growth of the tumor may be miraculously slowed down or stopped.
Katz: What’s the comparative situation in the male?
Ham: One example is cancer of the prostate gland. The prostate gland reaches full development under the influence of the male sex hormone. If the gland that makes the male sex hormone is removed by surgery, the patient may be greatly improved.
Katz: Are hormones used in therapy?
Gardner: Hormones arc probably the first chemotherapeutic agents (i.e. curing by drugs) to be used in cancer. We’ve used cortisone for leukemia . . .
Kaplan: . . . female sex hormones, injected into a man with cancer of the prostate will help him. And breast cancer in women can sometimes be controlled by injections of the male sex hormone.
Gardner: And we should mention the experiments we’ve done with mice. Certain hormones, applied directly to the uterine cervix of mice have produced cancer.
Will we find a drug to cure cancer?
Berton: Do you think we’ll ever find a drug that will cure all types of cancer or will we need to discover a different drug for each different kind?
Haddow: I think we’ll probably need several substances. It’s perfectly clear now that the disease has several causes; hence the need for several drugs.
Leblond: On the other hand, we shouldn’t be too pessimistic. Thirty years ago, medical researchers were looking for a cure for infectious diseases caused by bacteria. They thought they would have to find a specific drug to cure each disease. They -were quite surprised to discover that the antibiotic drugs were helpful in a wide range of infectious diseases. Now I don’t want to make this look too easy. I myself am working on tumors of the thyroid gland and I've already classified sixteen types of tumor. There seems to be a tremendous variety in these tumors and it's possible that we won't find any one substance that can attack all of them with the same efficiency.
Kaplan: I think we should explain to the public why the chemotherapy of cancer is so difficult as compared to treating infectious diseases like pneumonia or tuberculosis. In these infectious diseases you have a bacteria or a virus or a parasite that doesn't belong in the body. They are foreign agents and an antibiotic drug will single them out for attack and not damage the rest of the body. There’s no such difference between the cancerous cell and the normal cell. The cancer cell is simply an altered cell: it’s part of the body itself. The job of finding a drug that destroys the abnormal cell and not the normal cell is tougher than finding a drug that will discriminate between a foreign agent and the cells of the body.
Stock: This is an important point and it might make the public a little more patient with us.
Katz: What are the most promising new drugs developed for cancer?
Stock: The one that has interested us most in the past few years has been 6-mercaptopurine. It is particularly effective in leukemia when used in combination with another substance, azaserine.
(How effective are these drugs? The Sloan-Kettering Institute for Cancer Research with which Dr. Stock is associated collected statistics on this point. Of every one hundred leukemic children treated by antibiotics and blood transfusions, fifty died within four months; five survived for a year. With the new drugs, fifty survived for a year; others can be kept alive for two years or longer.)
Are some people immune to cancer?
RertMibluin: It's always been assumed that because some people get cancer and others don’t that the latter group has some kind of immunity. It may be proven some day, but it hasn't been yet.
Lacassagne: Looking at the problem another way, we are able to breed mice that are susceptible to certain types of cancer such as leukemia, the lungs and the breast.
"It may be there are more spontaneous cures in cancer than we suspect"
Berfon: Is it possible to breed strains of mice that are immune?
Katz: Could we do the same with human beings?
Lacassagne: We have no pure strain of men.
Katz: How about cases of spontaneous regression or cure—the patient whose tumor grows smaller or disappears for no apparent reason. What’s the explanation?
Berenbium: The conventional explanation is that they acquire immunity. There are other explanations but they would be too technical to go into.
Haddow: Some of these dramatic cures seem to be associated with hormonal changes, such as occur in pregnancy. 1 think these spontaneous cures are of tremendous importance to research and should be studied carefully. If we could discover exactly what happens, we could apply these findings to cancer patients.
Gardner: It may be that there are more spontaneous cures in cancer than we suspect. There may be many cancers that appear and then disappear before they get to the stage where they show clinical symptoms. This is certainly true from what we see in our laboratory experiments with mice.
Leblond: It might be interesting to point out that last year somebody did an autopsy on a large number of people who had not died of cancer. They examined the thyroid glands. A surprisingly high percentage contained malignant cancer ceils.
Berenbium: The same sort of observation was made when someone did a series of studies on the prostate glands of elderly men who also had not died of cancer. Cancer cells were discovered in a high proportion of cases.
Does smoking cause lung cancer?
Berenbium: The statistics that have been gathered are very striking but 1 don’t want to go too far beyond saying that. There’s also a correlation between the output of electric refrigerators and the incidence of lung cancer during the past few decades . . .
Kaplan: . . . and speaking of correlations, you can prove that skirts arc the cause of breast cancer, since the only people who get breast cancer wear skirts.
Berenbium: What l was saying was that scientists are very skeptical. They are not ready to jump to conclusions just because there’s a striking statistical relationship between two phenomena. They want other evidence to suggest there’s a true relationship.
Haddow: I think there's an important correlation between cigarette smoking and lung cancer—particularly since the heavier the smoking, the greater the incidence of cancer. Mind you, this doesn’t amount to positive proof but I have a strong feeling they’re connected.
Berenbium: I want to give you an example of why we’re so cagey about correlations. After all, when you're smoking a cigarette, you’re also burning the paper around it. There may he other factors associated with cigarette smoking causing the cancer, not the tobacco itself.
Kaplan: Even if we grant that the statistical proof that smoking and lung cancer are related, it doesn’t mean that smoking causes all lung cancer. There are probably several causes for every kind of cancer that a man gets.
Leblond: . . . for example, the air of the city is polluted with exhaust from automobiles and diesel engines. We know that these contain agents which are carcinogenic.
Ham: In the experimental work carried out in regard to this problem, tobacco tar was painted on the skin of mice for several weeks and they developed cancer. But heavy smokers invariably have their fingers stained with something from the cigarette smoke and who ever heard of anyone getting skin cancer from it?
added to food cause cancer?
Haddow: I think this problem should be seriously considered. As a matter of fact, it’s so important that a special international conference is to be held in Rome to consider this subject within a few months. Interest in this question goes back twenty-five years to the work of a number of English scientists who observed that there are many substances that can produce cancer in both animals and men. This prompted them to examine the substances that go into the things we eat. Certain forms of dyes, for example, are cancer-producing. Minute quantities of “butter yellow” used to be added to butter as coloring. When tested on rats, it was found to cause cancer of the liver.
Berenbium: Fortunately “butter yellow” is no longer used. But the problem of possible cancer agents in food still remains. it’s one of the results of the centralized. mass production of foods. Colors are put in to make them saleable, preservatives are used so that they'll stay fresh until they're sold. But very often we don't even know what these additives are. Many of us are consuming artificial substances in our food without knowing it. We mustn't become panicky and jump to the conclusion that all food additives are dangerous. At the same time, we must recognize that some of them may be dangerous and study them thoroughly.
“We musn’t panic about artificial substances in food. But we must recognize some may be dangerous"
Gardner: I'd have to go along with that.
Haddow: On dye in foods, 1 think the problem has arisen because it is often used before the biological properties are fully understood. 1 think we should have some kind of setup where all substances could be thoroughly tested and examined before they actually find their way into food.
Gardner: The general population does have a good deal of protection in this matter, of course. Our drug and food officials in the U. S.. for example, are always investigating sprays and insecticides used on edible plants. (The same is true of Canada.)
Can industrial fumes cause cancer?
Berenbluni: 1 think it has been substantiated that in a few manufacturing industries—such as chrome and nickel carbonyl—tumors are produced in some workers. The employers have since taken the necessary precautions to protect their workers.
Kaplan: Most industries, once they feel there's a problem, look into it carefully. For example. Standard Oil of New Jersey carried on an investigation to see whether cracked petroleum products had carcinogens in them. I hey did and they took the precautions to protect employees.
ees. Berenbluni: Industries, like people, have to be educated about the cancer hazard. At first, when it was established that in certain industries the workers might get tumors, the employers tried to censor this information and were secretive about manufacturing processes. They were afraid they might frighten workers off. But industry gradually learned that it was in its own. as well as the public, interest to co-operate with public-health authorities in carrying on research in the hazards of industry. In England there are several examples of industry and cancer-research groups working together.
Haddow: A good example would be the dye industry in England. With money supplied by the industry we investigated why some workers in dye factories contracted cancer of the bladder.
Is the radiology in detecting disease a hazard?
Haddow: The greatest radiation hazard is diagnostic radiology. Many of us feel it is carried out far too indiscriminately.
Berton: You mean the diagnosis may be more dangerous than the disease?
Kaplan: Not necessarily. As a radiologist. I'd like to come to the defense of my colleagues. We use X-ray investigations in cancer chiefly on older people— a group of people who are no longer reproducing. Their children won't be affected because they won't be having any more children at their age.
Haddow: When speaking of radiation hazards. I think we should keep in mind the dangers involved in using radioactive isotopes in treatment. We are now beginning to see the first cases of leukemia in patients on whom isotopes were used.
“Cancer surveys aren’t feasible. A few cancers might be detected, but many may be wrongly diagnosed”
Kaplan: I'd like to mention one other point as far as the use of radiology in diagnosis is concerned. We have a new type of electronic fluoroscope which gives a very bright and clear picture on the tluoroscope screen, while at the same time the amount of radiation that goes through the patient's body is much less than we used in older fluoroscopes.
Leblond: There's another radiation
hazard I'd like to mention—luminous wrist watches, clocks and car instrument panels. They are radioactive. Some people wear their watches on the inside of their wrist night and day, beaming radiation at their bodies. They may be in for trouble.
Katz.: Is it possible to get cancer from a wrist watch?
Leblond: From my calculations it’s quite possible.
Ham: I'm no expert on this topic but I've discussed it with two Canadians who know quite a bit about radiation— Dr. Robert Taylor and Dr. Harold Johns. They told me we shouldn't disregard the possible danger of luminous-faced instruments—they may have long-term genetic effects. On the other hand, they didn't appear to be too worried that the wearer of a luminous wrist watch ran much risk of getting cancer.
Is cancer education good or bad?
Katz: It's been claimed that cancereducation programs spread fear among the public? Do you share this view that knowledge makes people frightened?
Stock: On the whole cancer-education programs do good. Some of my friends have told me that they have frightened them. On the other hand, I think that most of us can point to individuals who have been saved from death as a result of information spread by cancer societies and other groups.
Lacassagne: We have a cancer-education week in France. We find that it sends thousands of people to the doctor’s office, many of them unnecessarily. I find that it's a bit of a problem knowing what you do tell and don't tell the public about cancer.
Berenblum: You have to take into account the population you're dealing with. In countries where people are phlegmatic you can tell them a great deal . . .
Katz: Such as?
Berenblum: Such as Sweden and England. In countries where the people are highly emotional you would have to be more restrained. On the one hand you have to tell people as much as possible so that they will be helped by your information. On the other hand, you don’t want them to think they have cancer every time they get an ache or pain.
Ham: Let’s look at the problem in a different way. Let's suppose that cancer and medical societies stopped giving out information about cancer. There would be a vacuum. In its place the public would pick up their knowledge of cancer from neighbors, friends or someone else who is probably not too well informed. Myths, misconceptions and fears about cancer would be widespread. I don't see that there's any choice but to continue doing what we're doing now— handing out accurate cancer knowledge that will help people to recognize early symptoms of cancer and go to their doctors immediately.
Kaplan: I don't want to question the value of public education, but I wonder if too much money isn't being spent on it and not enough on research. A Chicago researcher estimated that about thirty-five percent of all cancer patients on this continent are being cured. He then estimated that if every single patient had come for treatment at the earliest possible moment, the cure rate might have been boosted to fifty percent. This means that research has the job of curing the other fifty percent. In the United States, the cancer dollar is not being spent in accordance with this type of estimate.
Katz: How is the American cancer dollar being distributed?
Kaplan: Roughly, it’s being split evenly three ways: education, service and research. I think that anywhere from two thirds to three quarters of the money should be spent on research.
Katz: What is the breakdown in Canada, Dr. Ham?
Ham: Forty percent on research, thirty percent on welfare services, thirty percent on education programs for cancer.
Katz: What experiences has the Israel Cancer Society had with public education. Dr. Berenblum?
Berenblum: 1 think we probably have a different approach than the other countries. We don't have much money to spend on public education so we had to plan our expenditures carefully wdiere they would do the most good. We finally decided to use our budget in organizing refresher courses for general practitioners. These courses help them sharpen their skills in diagnosing cancer. This is a form of cancer education far different from the usual program of trying to educate the layman.
Would mass detection be useful?
Kaplan: I think the answer is an unqualified no! Detection in tuberculosis is relatively simple—it's usually the lung that's affected. It's economical and fast to survey that single organ. But to find cancer you'd have to conduct an extensive and expensive search of the whole body. The problem would be too complicated.
Haddow: 1 don't think mass-detection surveys are feasible. It's true, a few cancers might be detected. On the other hand, there would be many cases which would be wrongly diagnosed and the people involved would be given surgery and other treatment procedures not called for. There’s also the doubtful wisdom of exposing millions of people to regular X-rays. ^