Abortion and Breast
Cancer: The Link that Won’t Go Away
(Pamphlet Version)
Angela Lanfranchi,
M.D., FACs
There are many well established and well-known
causes of breast cancer, such as inheriting a BRCA gene (a defective gene
associated with increased breast cancer risk) and being exposed to oral
contraceptives and hormone replacement therapy. There are lesser known risks of
breast cancer such as cigarette smoking before a full term pregnancy and induced
abortion. But just as only 15% of people who smoke will get lung cancer and only
about 5 – 10% of women with breast cancer develop this cancer because they had
an abortion, we should still advise the public of these avoidable risks, however
small. Women need this information to make informed choices and to understand
when to get screened for cancer if they are at increased risk, beginning
approximately 8 to 10 years after the risk was taken.
Over fifty years ago, in April 1957, the first
study reporting a link between abortion and an increased risk of breast cancer
was published in a major medical journal. By 1995, after abortion was widely
legalized in the West, 17 studies worldwide showed a statistically significant
abortion-breast cancer link (or “ABC link”). Yet few medical professionals or
members of the public knew of these important studies.
Over the last thirty years, 48 million abortions
have been done on American women and breast cancer incidence has risen 40%.
Actuary Patrick Carroll, looking at data from several countries, concluded that
abortion is the greatest predictor of a country’s breast cancer rate.
Over ten years ago, in 1996, Dr. Joel Brind and
colleagues from Pennsylvania State University published a meta-analysis of all
the known published studies to date on breast cancer that distinguished between
induced and spontaneous abortions (miscarriages). That rigorous quantitative
analysis demonstrated a 30% increased risk of breast cancer in women who had an
induced abortion.
The Biology of Pregnancy
Outcomes and Breast Cancer Risk
Years of published research have shed light on
the breast maturation process that accounts for the protective effect of a full
term pregnancy. During pregnancy breasts enlarge, doubling in volume. Due to the
stimulating hormones estrogen and progesterone, the number of lobules (units of
breast tissue comprised of a duct and several milk glands) increases in
preparation for breast feeding. Under the influence of the pheromones hCG and
hPL, made by the baby in the mother’s womb, the mother’s breast also matures so
that cancer-vulnerable Type 1 and 2 lobules become cancer-resistant Type 3 and 4
lobules.
Most of the breast maturation needed for
resistance to breast cancer does not occur, however, until after 32 weeks of
pregnancy, gaining maximum protection at 40 weeks (full term). This is why a
premature delivery before 32 weeks more than doubles the risk of breast cancer.
About 23% of all pregnancies end in spontaneous
abortions (i.e., miscarriages) in the first 11 weeks (in the first trimester).
Abnormally low levels of pregnancy hormones do not stimulate the breasts to grow
a significant number of Type 1 and 2 lobules (the places where cancer starts).
Early miscarriage therefore does not increase the risk of breast cancer as does
induced abortion when terminating a normal pregnancy.
A woman who is pregnant can legally choose an
abortion or carry her baby to full term. By carrying her baby to full term, she
matures about 85% of her breast tissue to cancer resistant Type 3 and Type 4
lobules, thereby lowering her long-term breast cancer risk, just by that fact
alone.
The “independent risk,” i.e., leaving her breasts
with more places for cancer to start, is contested by some epidemiologic
studies, but is consistent with all known facts of breast development in texts
and literature. If pregnancy is interrupted, her breasts are left with more
cancer-susceptible lobules than when her pregnancy began.
If
abortion is so clearly linked to breast cancer, why do so few physicians and
women know about it?
Ideology, Breast Cancer and Abortion
Studies in the last ten years showing little or
no association between breast cancer and abortion have so many flaws that they
prompted Dr. Edward Furton, staff ethicist at the National Catholic Bioethics
Center, to write “The Corruption of Science by Ideology” in 2004. Dr. Furton
decried the “unwillingness of scientists to speak out against the shoddy
research that is being advanced by those who deny the abortion-breast cancer
link.”
For example, in 2004 the British journal
Lancet published a meta-analysis by Valerie Beral et al. of 52
abortion-breast cancer studies. Inexplicably, data from more than half the
studies selected by Beral (28 of 52) had not even been published in
peer-reviewed journals. She also excluded 15 peer-reviewed studies – whose
findings supported the ABC link – for invalid, non-scientific reasons.
A study by Karin Michels et al., published in the
April 2007 Archives of Internal Medicine, was reported in the New York
Times and other news outlets as showing “Breast Cancer Not Linked to
Abortion.” Particularly egregious was the deletion of an important adjustment
for spontaneous abortions from the overall result. This flaw alone reduced the
reported risk increase from an almost significant 10% to a non-significant 1%.
What May Cause the
Denial of the ABC Link?
First, while we may idealize scientists as being
above all personal biases and influences, the reality is that they, too, are
human and can be influenced by many things other than the facts. Those
influences may include cultural prejudices, sources of funding for research, and
even sheer resistance to new or unwelcome ideas.
In a 2005 study “Scientists Behaving Badly,” the
scientific journal Nature revealed that, in an anonymous questionnaire,
15.5% of scientists who received grants from the National Institutes of Health
admitted to changing study design, results and methodologies “in response to
pressure from a funding source.”
Ideology of “Safe” Abortion
This tendency to ignore or deny inconvenient
information is especially strong when the subject is abortion. Documentation and
public awareness of the negative effects of abortion poses a danger to Big
Abortion, in the same way studies linking cigarettes to cancer posed a danger to
Big Tobacco.
The first study linking cigarettes to lung cancer
was published in 1928, and the first Surgeon General’s warning, without the
support of the AMA, was announced in 1964. The Bradford- Hill epidemiologic
criteria developed to evaluate causality, ultimately used to show the tobacco-
lung cancer link in the 1960s, are the same criteria that support the ABC link.
The Abortion Breast Cancer Link is not likely to
be disproved, because this finding rests on the biological facts about our
created bodies. Pro-choice columnist Ellen Goodman in 2004 railed that research
linking breast cancer to abortion “keeps reappearing no matter how many
scientists drive a stake through its heart.” But the link is based on how we are
made, and this reality won’t ever go away.
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Angela
Lanfranchi, MD, FACS is a Clinical Assistant Professor of Surgery at UMDNJ
Robert Wood Johnson Medical School and Vice-President and cofounder of the
Breast Cancer Prevention Institute. She has been in private practice of surgery
since 1984 and specializes in the treatment of breast cancer.
The
full-length version of this article is posted at
http://www.usccb.org/prolife/programs/rlp/lanfranchi.pdf
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