=======================Electronic Edition========================
RACHEL’S ENVIRONMENT & HEALTH WEEKLY #418
—December 1, 1994—
News and resources for environmental justice.
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PREVENTING BREAST CANCER
(Last week’s discussion of “Big Picture organizing around human
health issues” will be continued next week.)
Cancer is uncontrolled growth of cells. Normal, healthy cells
grow by dividing; one cell divides and becomes 2 cells; those 2
divide and become 4 cells, and so on. Cell division is normal.
When a cell divides, its genetic molecules (called DNA, or
deoxyribonucleic acid) are reproduced in its descendants, the new
cells. The genetic molecules (the DNA) contain complete
instructions telling the new cells how to function, how to
behave, including how (and how fast) to divide.
Normal DNA also contains instructions telling cells when to stop
dividing. Normal cell division always stops at some point, by
natural means; none of us continues to grow forever. When cells
fail to stop dividing, they can continue to grow until they kill
their host (the person whose body contains the runaway cells).
This is cancer.
Cancer is now thought to be a genetic disease, or, more properly,
about 100 different genetic diseases. According to current
medical theory, a cancer tumor develops in stages, starting from
a single cell. [1] As a cell accumulates a series of “genetic
lesions,” a full-blown cancer can begin. A lesion is an injury
or loss of function. Genetic lesions are lesions that occur in
the DNA molecules that control a cell’s proper operation,
including the accuracy and appropriate rate of cell division.
Genetic lesions in a cell can occur at any age, including the
time when a fetus is forming in its mother’s womb.
Some genetic lesions can be inherited from parents. In other
words, some people start life with DNA that has been damaged in
some way. Such inherited lesions are present in the fertilized
human egg, the single cell from which the new person will grow.
Since every cell in a person’s body is descended from that first
cell (the fertilized egg), the inherited DNA lesion is present in
every cell in the new person’s body.
In contrast to an inherited lesion, which affects every cell, a
person can also develop a genetic lesion during childhood or as
an adult. Such a lesion affects the single cell that first
acquired the damage (from exposure to ionizing radiation, or
certain chemicals, for example); it will also affect any cells
that are descendants of that particular cell, but it will not
affect unrelated cells in the body.
Cancer is thought to develop after a cell has accumulated several
cancer-causing lesions. Medical authorities commonly estimate
that 4 to 10 lesions in a cell’s DNA are necessary before a
cancer can develop. Some of these lesions may be inherited, and
others may be acquired at any age after conception. If this
theory is correct, the vast majority of people are not “destined”
to get cancer, even though they may inherit a cancer-causing
genetic lesion from one of their parents. If they are prudent
and avoid unnecessary exposures to carcinogenic materials (such
as radiation and certain chemicals), get adequate exercise, and
eat a healthy diet rich in anti-cancer foods (such as dark green
and yellow/orange vegetables, and fruits), they can reduce their
chances of developing a tumor.
A few people inherit powerful genetic lesions that confer a high
chance of getting cancer in a specific organ, with the cancer
often occurring at a young age. Such powerful inherited lesions
seem to account for 5 to 10 percent of all human cancers. Even
these powerful inherited lesions may need additional lesions
before they can turn into a cancer. The relationship of inherited
lesions, and lesions that develop later, are poorly understood.
It may turn out that cancer never develops without an inherited
“head start” and almost always requires the interaction of an
inherited lesion with other forces. The “other forces” would be
pesticides or pesticide by-products, carcinogens in the diet,
certain industrial chemicals, inadequate exercise, EMFs
(electromagnetic fields), ionizing radiation, and so on.
This theory of cancer implies that a large proportion of all
cancers can be avoided or eliminated if we correctly identify and
eliminate the non-inherited forces which act alone, or act along
with inherited lesions, to produce cancer.
As we saw last week, the rates of incidence (occurrence) of 19
kinds of cancer are increasing in the U.S., and the death rates
for 12 kinds of cancer are increasing. (Those cancers for which
incidence rates are rising and death rates are falling are the
cancers we are “learning to live with.” They are: cancers of the
colon/rectum; larynx; testicles; bladder; Hodgkin’s disease;
childhood cancers; leukemia; and thyroid. People are surviving
these cancers because of surgery, chemotherapy, and radiation
treatments. Although it is good news that more people are
surviving these cancers, it is hard to argue that this is an
unqualified medical success because the quality of life for
cancer survivors, and their families, is often wretched.)
Among the most rapidly-increasing and PREVENTABLE cancers is
breast cancer. In the U.S., about 182,000 new cases of breast
cancer will be reported in 1994 (1000 in men, 181,000 in women);
and about 50,000 American women now die each year from breast
cancer.
In a new book to be published in February, 1995, Dr. John Gofman
presents compelling evidence that about 75 percent of breast
cancer is caused by exposure to ionizing radiation, principally
from medical x-rays. In his usual fashion, Gofman argues
methodically and carefully, clearly explaining all assumptions,
and all calculations. Gofman demonstrated in his earlier books [2]
that he is one of our greatest teachers; this new book provides
additional evidence of his gift.
Gofman quotes people who say, “We know nothing about the causes
of breast cancer.” He is appalled that in 1994 anyone could make
such claims. He cites a series of studies, dating back to 1965,
which showed that exposure to ionizing radiation is a prominent
and proven cause of breast cancer.
In 1961, Dr. Ian MacKenzie, a physician in Nova Scotia, examined
a patient with rapidly-growing breast cancer. He noticed that
the skin on her chest showed signs of radiation burns. She
explained that she had had tuberculosis and that, as part of her
treatment, she had had “artificial pneumothorax therapy” (one of
her lungs was intentionally collapsed); this therapy included
about 200 fluoroscopic x-rays of her lungs. (A standard x-ray
makes an snapshot image on photographic film; in fluoroscopy,
examination of a patient takes place while the x-ray beam stays
turned on so the physician can observe what happens when the
patient, or the patient’s organs, are in motion. Fluoroscopes
deliver a much larger dose of radiation than normal x-ray
snapshots.)
Dr. MacKenzie then studied 800 women who had been treated for
tuberculosis in one hospital between 1940 and 1949. He found
that women who had not had “artificial pneumothorax therapy” had
a 1-in-510 chance of getting breast cancer; women who had had the
therapy had a one-in-21 chance of getting breast cancer. In
other words, women who had had many fluoroscopic exams of their
lungs had 24 times as great a chance of getting breast cancer as
women who had avoided fluoroscopy. [3]
MacKenzie’s work caused quite a “stir” in the radiation
community. Happily, it stimulated a Japanese researcher, C. K.
Wanebo, to examine the data gathered from the atomic bombings of
Hiroshima and Nagasaki in Japan in 1945. In 1968, Wanebo
reported that radiation exposure at Hiroshima and Nagasaki had
caused a demonstrable increase in breast cancers among surviving
women. [4]
Since then, numerous scientific and medical papers have confirmed
that ionizing radiation causes breast cancer. The latest
confirmation, based on further analysis of A-bomb survivors, was
published in 1994. [5]
Several other factors besides radiation have been linked to
breast cancer: age at which a women’s period begins (later is
safer); age at which menopause occurs (earlier is safer); age at
birth of first child (earlier is safer); diet (less fat and more
fiber are safer); alcohol intake (less is safer); and exercise
(more is safer). All of these factors have a common thread: they
all affect the estrogen levels in a woman’s blood stream.
However, these known “risk factors” only account for 30% of
breast cancers; some 70% remains unexplained.
Dr. Gofman’s most recent analysis (which he first presented at
the annual meeting of the American Association for the
Advancement of Science in February 1994) [6]indicates that the
“other 70%” can be explained by excessive exposures to radiation,
most of it medical radiation. This does not mean that the “other
factors” (such as pesticides, and so forth) are unimportant. The
multi-step genetic model of cancer development (described above)
permits contributions even to a single case of cancer from
heredity, ionizing radiation, viruses, hormone pills, chemicals,
and other factors as well. Dr. Gofman believes that radiation is
a MAJOR cause, not the ONLY cause.
Gofman argues in his new book that most breast cancer can be
prevented by reducing women’s exposure to medical radiation
WITHOUT denying women the benefits of diagnostic radiology. This
is an important book.
GET: PREVENTING BREAST CANCER: THE STORY OF A MAJOR, PROVEN,
PREVENTABLE CAUSE OF THIS DISEASE. It will be available for
$15.00 in February, 1995, from: The Committee for Nuclear
Responsibility (CNR), P.O. Box 421993, San Francisco, CA 94142.
                
                
                
                
    
–Peter Montague
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[1] This week’s newsletter contains long paraphrases and
unattributed quotations from work by John Gofman and Egan
O’Connor of the Committee for Nuclear Responsibility (CNR), P.O.
Box 421993, San Francisco, CA 94142. However, any errors of
interpretation are ours and not theirs.
[5] Four-part supplement on atomic bomb survivors in RADIATION
RESEARCH Vol. 137 Supplement (1994).
Descriptor terms: ionizing radiation; breast cancer; dna;
genetic disorders; diet; antioxidants; pesticides; emfs;
electromagnetic fields; cancer statistics; john gofman; egan
o’connor; committee for nuclear responsibility; iam mackenzie;
fluoroscopy; x-rays; x-radiation; hiroshima; nagasaki; atomic
bomb; nuclear weapons; estrogen;