What Is Cancer? What Causes It?
PERHAPS deservedly, over the years the word “cancer” has acquired a strong negative overtone. Phrases such as “spreading like a deadly, insidious cancer” have impelled many people to close their minds to the word and its true significance.
Yet, today, when brought out into the open in an objective manner, the subject assumes less fearsome proportions. Instead of always being “deadly,” it often becomes “curable.” Instead of always “spreading,” it is often terminated while still localized. So, what is cancer really? And what causes it?
British experts Sir Richard Doll and Richard Peto explain: “The various human cancers are diseases in which one of the many cells of which the human body is composed is altered in such a way that it inappropriately replicates itself again and again, producing millions of similarly affected self-replicating descendant cells, some of which may spread to other parts of the body and eventually overwhelm it.”—The Causes of Cancer.
The big question now is why? Why do some cells break out of the normal mold and proliferate abnormally?
Does Your Life-Style Make a Difference?
At the present stage of cancer research, doctors have a far-from-complete answer to the cancer scourge. The fact that it is increasing is confirmed by Drs. John C. Bailar III and Elaine M. Smith who recently stated in The New England Journal of Medicine: “From 1973 to 1981 the crude incidence rate for all neoplasms [cancers] combined rose by 13.0 percent. . . . There is no reason to think that, on the whole, cancer is becoming any less common.”
To a great extent, the cancer experts are caught between the need to find an adequate treatment for malignant tumors and the need to encourage prevention by tracing the true causes. The search for causes leads to a labyrinth of differing theories—does the cause lie in viruses, genes, immune responses, chemicals, environment, toxics in the body, in combinations of these, or in something else? And by what process does a cell become malignant and then migrate?
A cancer expert, Professor Stephan Tanneberger, stated: “It is now an established fact that this is a process involving several stages whereby a normal cell with a certain genetic make-up is transformed into a tumour cell under the influence of several factors. We know that viruses, radiation and chemical substances constitute such factors, but it is safe to say that only the interaction of several such factors produces a cancer cell in a multistage process.”—Prisma.
What does this mean for us in everyday life? According to Dr. Charles A. LeMaistre, president of the American Cancer Society, our daily living habits have a bearing on the causes of cancer. He stated: “Most scientists now believe that our daily habits—what we eat and drink, whether we smoke and how often we expose ourselves to the sun determine to a great extent our risk of getting many cancers.”—Ebony magazine.
This point of view is confirmed by the research of University of Oxford experts Doll and Peto. They state: “Observations of the vagaries of human behavior may suggest ideas that might never occur to a laboratory investigator. Historically, they provided the starting point for a large part of all cancer research by pinpointing the risks associated with exposure to the combustion products of coal, sunlight, X-rays, asbestos, and many chemical agents. They drew attention to the hazards associated with chewing various mixtures of betel, tobacco, and lime and with smoking tobacco.”
Since life-styles and environments differ from one country to another, it means that there is a tendency for some countries to have more of some types of cancer and less of others. For example, England, where tobacco use has been prevalent for decades, leads in lung cancer. Nigeria, which has not caught up in tobacco usage, has a much lower incidence of that ailment at present. Connecticut, U.S.A., leads in colon and bladder cancer, while Nigeria has the lowest levels.
Another example of how life-style can be conducive to cancer is Kaposi’s sarcoma, a normally rare cancer. Homosexuals have been stricken with it in the last few years as a consequence of AIDS, which weakens the patient’s immune system and lays him open to infections and this sarcoma.
A possible additional factor in causing cancer is indicated by Dr. Kenneth R. Pelletier of the University of California School of Medicine: “Numerous animal and human experimental studies have demonstrated that stress, psychological depression, and other psychosocial factors compromise an organism’s capacity to prevent the induction of disease such as cancer or limit its spread.”—Holistic Medicine.
Other doctors also hold this view that excessive stress can affect the immune system and thus lay a person open to cancer and other diseases. Now let us look more closely at some of the more obvious causes of cancer.
Tobacco—A Deadly Foe
For decades tobacco has been linked to cancer. Therefore it causes no great surprise to read the following press release: “The World Health Organization, citing a report that nearly one million deaths each year can be attributed to tobacco use, has issued a strong condemnation of smoking and tobacco use.” That item, published in The New York Times, went on to say that “smoking is responsible for 90 percent of all cases of lung cancer, 75 percent of all cases of chronic bronchitis and emphysema and 25 percent of ischemic heart disease as well as other types of cancer, pregnancy complications and respiratory diseases.”
Tobacco plays such an important role in cancer that Dr. Byron J. Bailey, University of Texas Medical Branch, believes that tobacco addiction should be called tobaccoism, and its consequence, cancer. He wrote in JAMA (Journal of the American Medical Association): “We must realize that tobaccoism is the most deadly drug addiction in the United States [in the world!] today and that it is exacting a heavier toll in lives and dollars than cocaine, heroin, the acquired immunodeficiency syndrome, traffic accidents, murder, and terrorist attacks combined.”
But what about the use of what is known as “smokeless tobacco,” snuff and chewing tobacco, now popular with millions of people worldwide? The New England Journal of Medicine reports that “in India, parts of Central Asia, and Southeast Asia, oral cancer is far more frequent than in the United States. In fact, it is the most common cancer in that area.” The report continues: “Smokeless tobacco taken orally, alone or together with such ingredients as areca nut and piper betel leaf and lime, has been shown to increase the risk of mouth cancer greatly.”
Tobacco and Alcohol—Is There a Link?
What can be said about smoking and drinking in combination? Drs. Doll and Peto affirm that alcohol “‘interacts’ with smoking, each agent enhancing the other’s effects. That alcohol is involved in the production of cancer has been suspected for 60 years, since it was shown that cancers of the mouth, pharynx, larynx, and esophagus were commoner than average in men who were employed in trades that encouraged the consumption of large amounts of alcohol.”
This conclusion is confirmed by the German cancer expert Professor Tanneberger, who said: “Smoking and excessive drinking are a risk factor of the first order. . . . There’s no escaping the fact that a causal relationship exists between a person’s mode of life and the development of cancer.”
Millions of people every year expose themselves to a random killer that seems so enjoyable and innocent—sunrays. Yet excessive sunbathing, especially if it leads to severe sunburn in adolescence, can be conducive to melanoma, a dark pigmented cancer of the skin. As one medical source explains: “The conditions that maximize risk may be those that involve sudden exposure of untanned skin to sunlight.”—The Causes of Cancer.
This cause should not be viewed lightly, since, in the United States alone, 23,000 new cases and 5,600 deaths are expected this year. Those most easily affected are people with light complexions, blue eyes, blond or red hair, and freckles.
Excessive exposure to X rays in medical examinations may be another “innocent” cause of cancer. For example the “rapid increase in incidence . . . is greater for thyroid cancer than for any other type of tumor and may in part be explained by the epidemic of non-fatal thyroid cancers induced by medical use of X-rays.”—The Causes of Cancer.
Even the food we eat may be another unsuspected cause of cancer. “Studies suggest that certain foods and some nutrients contained in those foods may be associated with the development of cancer. Findings suggest that a high intake of dietary fat is a risk factor for cancer. . . .
“Scientists have found some relationship between a lack of certain vitamins—A and C—and cancer. For example, diets low in vitamin A have been linked to cancers of the prostate gland, cervix, skin, bladder and colon.”—U.S. Department of Health and Human Services.
One curious example is that of aflatoxin, “a product of the fungus Aspergillus flavus that commonly contaminates peanuts and other staple carbohydrate foods stored in hot and humid climates.” According to Drs. Doll and Peto, it “is a major factor in the production of liver cancer in certain tropical countries.”
After Cause and Effect—What Next?
The fact of the matter is that there are at least 200 different types of cancer with many distinct or interrelated causes. In some cases, the causes are still not known for sure. Chemicals used in food, as well as industrial pollutants, have been pinpointed as possible causes. For some reason, delay in having a first child, thus delaying natural lactation, also has some bearing on the incidence of breast cancer. For further information on causes of cancer, see the box on page 6.
If scientists have established that many cancers are due to human behavior and factors in the environment, we are on the way to important solutions to the cancer problem—prevention and cure. These will be dealt with in the following article.
[Box on page 5]
Definitions of Cancer Terminology
Tumor—an abnormal mass of tissue; any unhealthy swelling; also called a neoplasm, or new growth. It can be benign or malignant.
Benign—cells that do not invade or infiltrate other tissue. However, a benign tumor can cause dangerous pressure.
Malignant—cells that invade and infiltrate surrounding tissues and, unless arrested, eventually overwhelm the patient.
Cancer—a malignant tumor. Cancers are listed under two main groups: sarcomas and carcinomas.
Sarcomas—cancers of the structural and connective tissues, including bones, cartilage, fat, and muscle.
Carcinomas—cancers that affect the tissues that cover or line body organs such as the skin, intestines, lungs, and breasts.
Carcinogen—a cancer-causing substance.
Metastasis—transmission of a disease from its original source to additional sites in the body.
Lymph—a clear fluid circulating through the body. It contains white blood cells, antibodies, impurities, and nourishing substances.
Lymph glands—or nodes. These normally filter impurities from the body. The lymph system is vital in the body’s defense against infection.
(Based on Cancer and Vitamin C, by Drs. Ewan Cameron and Linus Pauling; The Facts About Cancer, by Dr. Charles F. McKhann.)
[Box on page 6]
Some Established Cancer-Causing Agents in Humans
Cause Cancer site
Aflatoxin (on moldy peanuts)‐‐‐‐‐‐‐‐‐Liver
Alcoholic drinks in excess‐‐‐‐‐‐‐‐‐‐Mouth, throat, esophagus, liver
Asbestos‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Lung, pleura, peritoneum
Chewing betel, tobacco, lime‐‐‐‐‐‐‐‐Mouth
Furniture (hardwood)‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Nasal sinuses
Leather goods‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Nasal sinuses
Overnutrition (causing obesity)‐‐‐‐‐Endometrium, gallbladder
Late age for first pregnancy Breast
Childless or very few children‐‐‐‐‐‐Ovary
Schistosoma haematobium, Africa‐‐‐Bladder
Chlonorchis sinensis, China‐‐‐‐‐‐‐Liver
Sexual promiscuity‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Cervix uteri; skin
Tobacco‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Mouth, throat, lung
Virus (hepatitis B)‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Liver
(Based on The Causes of Cancer)