What Causes Breast Cancer ?
by Peter Montague
Environmental Research Foundation
P.O. Box 5036, Annapolis, MD 21403
Fax (410) 263-8944; Internet: email@example.com
Breast cancer kills 46,000 women in the U.S. each year. On
average, each of these women has her life cut short by 20 years,
for a total loss of about a million person-years of productive
life each year. Of course this huge cost to society is heaped
on even greater burdens, the personal anguish and suffering, the
motherless children, the shattered families.
The medical establishment dominated by male doctors pretends
that the breast cancer epidemic will one day be reversed by some
miracle cure, which we have now been promised for 50 years. Until
that miracle arrives, we are told, there is nothing to be done
except slice off women's breasts, pump their bodies full of toxic
chemicals to kill cancer cells, burn them with radiation, and
bury our dead. Meanwhile, the normal public health approach primary
prevention languishes without mention and without funding. We
know what causes the vast majority of cancers: exposure to carcinogens.
What would a normal public health approach entail? Reduce the
burden of cancer by reducing our exposure to carcinogens. One
key idea has defined public health for more than 100 years: PREVENTION.
But with cancer, everything is different. In the case of cancer,
prevention has been banished from polite discussion.
Now a new, fully-documented book, by physician Janette
D. Sherman, poses a fundamental challenge to all the doctors and
researchers and health bureaucrats who have turned their backs
on cancer prevention: "If cancers are not caused by chemicals,
endocrine-disrupting chemicals, and ionizing radiation, what are
the causes? How else can one explain the doubling, since 1940,
of a woman's likelihood of developing breast cancer, increasing
in tandem with prostate and childhood cancers?," Dr. Sherman
asks.(pg. x) And if exposures are the problem, then ending exposures
is the solution: "Actual prevention means eliminating factors
that cause cancer in the first place."(pg. 31)
Dr. Sherman is a practicing physician who has treated 8000
patients over 30 years. Unlike most physicians, she possesses
an extensive knowledge of chemistry. Furthermore, she has become
a historian by examining a large body of medical and public health
literature dating back to the 19th century. It is this unique
combination -- of historical view, knowledge of chemistry, deep
personal experience as a physician, and an ethical clarity that
PRIMARY PREVENTION is the proper policy -- that makes this book
important and compelling.
The book begins with two chapters emphasizing the similarities
among all living things that are made up of cells including humans,
animals and plants. Cells in every creature can go awry and start
to grow uncontrollably, a definition of cancer. Because all cell-based
creatures are so similar, what we learn from one can often tell
us something useful about another. For example, when we learn
from the Smithsonian Institution that sharks get cancer from swimming
in waters contaminated with industrial chemicals, we learn (or
SHOULD learn) something useful about our own vulnerability to
exotic chemicals.(pg. 9)
Turning to breast cancer, Dr. Sherman lists the known "risk
factors" the common characteristics shared by many women
who get breast cancer: early menarche (age at which menstruation
begins); late menopause (age at which menstruation ends); late
childbirth and the birth of few or no children; no experience
breast-feeding; obesity; high fat diet; being tall; having cancer
of the ovaries or uterus; use of oral contraceptives; excessive
use of alcohol.
"What is the message running through all of these 'risks?'"
Dr. Sherman asks. "Hormones, hormones, and hormones. Hormones
of the wrong kind, hormones too soon in a girl's life, hormones
for too many years in a woman's life, too many chemicals with
hormonal action, and too great a total hormonal load."(pg.
Dr. Sherman then turns her focus to the one fully-established
cause of breast (and other) cancers: ionizing radiation, from
x-rays, and from nuclear power plant emissions and the radioactive
fallout from A-bomb tests.
These, then, are the environmental factors that give rise
to breast cancer: exposures to cancer-causing chemicals, to hormonally-active
chemicals, and to ionizing radiation in air, food and water. How
do we know the environment air, food, water and ionizing radiation
plays an important role in causing breast cancer? Because when
Asian women move from their homelands to the U.S., their breast
cancer rate soars. There is something in the environment of the
U.S. (and other western industrial countries) causing an epidemic
of this hormone-related disease. The medical research establishment
likes to call it "lifestyle factors" but it's really
environment. Air, food, water, ionizing radiation.
With this basic information in hand, Dr. Sherman then describes
historically and today the exposure of women in the U.S. to a
flood of carcinogenic and hormonally active chemicals, plus ionizing
Take common pharmaceutical products, for example. Canadian
researchers have demonstrated enhanced cancer growth in mice given
daily HUMAN-EQUIVALENT doses of three commonly-used antihistamines,
which are sold under the trade names Claritin, Histamil and Atarax.(pg.
21) Two years earlier the same researchers had reported breast
cancer promotion in rodents fed clinically-relevant doses of antidepressant
drugs, which are marketed as Elavil and Prozac.(pg. 21) Millions
of women in the U.S. are taking these drugs today.
At least 5 million women in the U.S. are currently taking
Premarin the most often-prescribed form of estrogen (female sex
hormone), to ease the transition through menopause.(pg. 156) This
is called "hormone replacement therapy" and it is routine,
recommended medical practice in the U.S. A review of 51 studies
of women taking hormone replacement therapy showed that those
who never took hormones had a breast cancer rate ranging from
18 to 63 per 1000 women. Those who took hormones for five years
showed an excess of 2 breast cancers per 1000 women; after 10
years of hormone therapy the excess breast cancer rate rose to
6 per 1000. The danger largely disappears 5 years after discontinuing
Hormones are big business. Despite evidence that synthetic
hormones caused cancer in rodents and rabbits, American drug companies
began selling synthetic hormones in 1934 in cosmetics, drugs,
food additives, and animal feed. The best-known is DES (diethylstilbestrol)
but there were and still are many others. The National Cancer
Institute (NCI) in 1938 published a study showing that DES caused
breast cancer in rodents. Three years later, in 1941, NCI published
a second study confirming that DES caused breast cancer in rodents.
That year the U.S. Food and Drug Administration (FDA) approved
DES for commercial use in women.(pg. 91)
DES is 400 times as potent as natural estrogen and can be
made for pennies per pill. It was therefore phenomenally profitable
and researchers aggressively sought new uses. DES soon was being
used to prevent miscarriages, as a "morning after" pill
to prevent pregnancies, and as a breast-enlargement cream. It
wasn't long before researchers discovered that they could make
chickens, cows and pigs grow faster if they fed them hormones,
and a huge new market for hormones opened up. As early as 1947,
a hormonal effect was reported among U.S. women who ate chicken
treated with growth hormones. (Chapter 7, note 55.) Between 1954
and 1973 three quarters of all beef cattle slaughtered in the
U.S. grew fat on DES.
In 1971, human cancer from DES exposure was confirmed and
in 1973 DES was banned from meat, so other growth hormones were
substituted. Most recently, of course, the U.S. FDA has allowed
the U.S. milk supply to be modified to increase the levels of
a growth hormone (called IGF-1) known to stimulate growth of breast
cells in women. (pg. 101)
Still today most U.S. beef, chickens and pigs are intentionally
contaminated with growth hormones which is why Europeans refuse
to allow the import of U.S. beef. European scientists are asking
the same question that Dr. Sherman raises: "[H] ormones are
administered to meat animals to promote growth and weight gain.
Why should humans expect to not respond similarly to such chemical
Then of course there are dozens probably, in fact hundreds
of household chemicals and industrial byproducts that are hormonally
active: pesticides, cleansers, solvents, plasticizers, surfactants,
dyes, cosmetics, PCBs, dioxins, and so forth, that interfere with,
or mimic, naturally-occurring hormones. We are awash in these,
at low levels, from conception until death.
How many growth-stimulating and cancer-promoting hormones
can we ingest or absorb through our lungs and skin before we feel
the effects? No one in authority is asking that crucial question,
but Janette Sherman is asking it, pointedly, and armed to the
teeth with scientific evidence.
Then there is radioactivity. In 1984, a study of Mormon families
in Utah downwind from the nuclear tests in Nevada reported elevated
numbers of breast cancers.(pg. 65) Girls who survived the bombing
of Hiroshima are now dying in excessive numbers from breast cancer.
Dr. John Gofman has reviewed 22 separate studies confirming unequivocally
that exposure to ionizing radiation causes breast cancer. (See
REHN #693.) Janette Sherman does a good job of summarizing ecological
studies showing that women living near nuclear power plants suffer
from elevated numbers of breast cancers. These studies, by their
nature, are suggestive and not conclusive. but there is ample
reason to believe that all nuclear power plants leak radioactivity
routinely into local air and water and that any exposure to ionizing
radiation increases a woman's danger of breast cancer. The only
way to PREVENT this problem is to end nuclear power permanently.
Why has the U.S. turned its back on the preventive approach
to cancer? Dr. Sherman returns to this question throughout her
book. For example, in a devastating chapter on Tamoxifen (a known
cancer-causing chemical now approved by U.S. FDA for use in women),
she asks, "Why is our primary well-funded National Cancer
Institute not devoting its efforts to primary prevention? Has
breast cancer, like so many aspects of our culture, become just
another business opportunity?"(pg. 149)
In the end, Dr. Sherman reaches a conclusion about that question:
"There is a massing, in a few hands, of the control of production,
distribution and use of pharmaceutical drugs and appliances; control
of the sale and use of medical and laboratory tests; the consolidation
and control of hospitals, nursing homes, and home care providers.
We are no longer people who become sick. We have become markets.
Is it any wonder that prevention receives so little attention?
Cancer is a big and successful business!" (pg. 207)
And, finally: "Reflecting on the purpose of the corporation
to sell products and services and maximize profits, it becomes
apparent that prevention cannot be in the interest of the bottom
line. What a sad and bitter realization," she concludes.(pg.
Despite this sad and bitter conclusion, this is a powerful
upbeat book about what citizens can and must do to end the epidemic
of cancer that is sweeping the western world. If the truth shall
set us free, this book is an important part of our collective
liberation, freeing us from the lies and deceptions, the false
promises of cancer cures always "just around the corner."
Cancer is caused by exposure to carcinogens. The way to solve
the cancer problem is to prevent exposures. This means we must
end nuclear power, and demand clean food, water and air. Janette
Sherman's contribution has been to give us a wealth of powerful
evidence on which to act. Now it is up to us.