The Great Cancer Myths

Cancer is a dreadful disease. In most polls, it is the most feared disease of all. Coupled with this are the almost daily media reports of another carcinogen or cancer risk being found in our environment that produce a setting for the sometimes hysterical fear that cancer lurks around every corner. Epidemiological pronouncements that one out of eight women will die of breast cancer or one of every four men will get prostate cancer, while perhaps having some statistical validity if everyone would reach age 80 and die of nothing else, belies the real risk of getting and dying of cancer. A study published by Wo-loshin et al.151 puts this rate in a more rational context.

These authors have developed charts for men and women that show the chance of dying from various causes based on age and smoking history (Figs. 3-11 and 3-12). Instead of giving risks in terms of population percentages, these data show risk in terms of individual risks. For example, their data indicate that a 60-year-old woman, even one who smokes, has a 4.5% chance of dying of a heart attack in the next decade, a 6.5% chance of dying of lung cancer, and a 0.7% chance of dying of breast cancer. Or to look at it another way, for every 1000 60-year-old women who are smokers, 45 will die of heart attacks, 65 of lung cancer, and 7 of breast cancer in the next 10 years. For 60-year-old women who have never smoked, 14 of 1000 will die of heart disease, 5 of lung cancer, and 7 of breast cancer by the time they reach 70 years of age. For 60-year-old men who are smokers, 84 of 1000 will die of heart disease and 98 of lung cancer, but only 4 of 1000 will die of prostate cancer.

A few years ago there was debate about whether the incidence of childhood cancers is going up, with the Environmental Protection Agency and the National Cancer Institute taking opposite points of view.152 Data obtained between 1975 and 1995 showed a slight increase in cancers of children, which appeared to be due to an increase in brain cancer. However, the rates of leukemia and lymphoma, which together account for about 35% of all childhood cancers, did not change. Since there are only about 1800 new cases of brain cancer in the United States per year, a small number of patients being diagnosed in any given year could skew the numbers. This is not to belittle the devastating effects of childhood cancer, but it must be kept in mind that cancer in children is a rare disease, about one-third of which is due to leukemia, and for which the overall 5-year survival rate for all childhood cancers combined is 70% to 94%.

While there is a tendency to blame environmental causes for cancer in children, this probably plays a small role. Hereditary gene mutations probably play a larger role. Most experts agree that a mother's smoking during pregnancy, electromagnetic fields from power lines, or other environmental toxicants play little role.152

There are always debates about what is or is not a human carcinogen. Many of them have been identified by occupation, a rare medical exposure, atomic bomb fallout, or viral or other infections. Determination of whether a chemical is a human carcinogen by high-dose exposure in rodents, frequently at doses that no human being would ever be exposed to, is notoriously inaccurate and has led to many false-positive claims. Another point of view is expressed by Bruce Ames, who has said that he is a ''contrarian in the hysteria over tiny traces of chemicals that may or may not cause cancer. If you have thousands of hypothetical risks that you are supposed to pay attention to, that completely drives out the major risks you should be aware of,''153 which I would add include

Figure 3—11. Risk chart for women who have never smoked. The chart indicates the number of women per 1000 who will die from various diseases and for any reason during the next 10 years, beginning at the indicated age. (*The numbers of each row do not add up to the chance of dying from any reason because there are many other causes of death in addition to the ones listed here.) Shaded area indicates age group and disease combinations with fewer than 1 death per 1000. (From Woloshin et al.,151 with permission.)

Figure 3—11. Risk chart for women who have never smoked. The chart indicates the number of women per 1000 who will die from various diseases and for any reason during the next 10 years, beginning at the indicated age. (*The numbers of each row do not add up to the chance of dying from any reason because there are many other causes of death in addition to the ones listed here.) Shaded area indicates age group and disease combinations with fewer than 1 death per 1000. (From Woloshin et al.,151 with permission.)

cigarette smoking, obesity, lack of antioxidants in the diet, sun overexposure, and inadequate access to health care in large parts of the United States and the world.

It has often been said that we live in a sea of carcinogens. Indeed, every time you're stuck in traffic or behind an exhaust-belching truck, you are inhaling a lung-full of potential carcinogens. If you live in a city and and drink chlorinated water, you are exposing yourself to a host of potential carcinogens. Most of the modern conveniences that we take for granted contain carcinogenic substances. The chair you sit in probably has polyurethane, another carcinogen, in the cushions. Another point is that modern technology such as high-sensitivity mass spectrometers can detect parts per billion of chemical substances. Thus, one must ask, is the detection of any level of a carcinogen dangerous? Perhaps it is worth keeping in mind an old adage in pharmacology: ''a tiny amount of something doesn't necessarily cause anything and enough of something can cause anything.''

Described below are some commonly held myths about agents that cause cancer.

Stop Smoking, Kick The Habit Now

Stop Smoking, Kick The Habit Now

Now You Can Quit Smoking And Start Living a Healthy Life Yes, You! Have You Ever Thought There’s No Way You Can Give Up Cigarettes Without Losing Your Mind? Well, Worry No More.

Get My Free Ebook


Post a comment