Abortion and breast cancer:
update on evidence of a causal
association
Joel Brind, Ph.D.
Professor of Human Biology and
Endocrinology
Baruch College, CUNY, New York, NY and
Breast Cancer Prevention Institute,
Somerville, NJ
April, 1957
[GANN, Vol. 48, Supplement; April, 1957]
AN EPIDEMIOLOGICAL STUDY ON CANCER IN JAPAN
The Report of the Committee for Epidemiological Study on Cancer,
Sponsored by the Ministry of Welfare and Public Health
(Chairman: Dr. Tomosaburo Ogata)
Tabulated and analysed by
M. SEGI, I FUKUSHIMA, S. FUJISAKU, M. KURIHARA,
S. SAITO, K. ASANO and M. KAMOI
(Department of Public Health, Tohoku University Medical School, Sendai, Japan)
 1970, 43, 209-221
Bull. Org. mond. Santé
Bull. Wld Hlth Org.
Age for First Birth and Breast Cancer Risk *
B. MACMAHON, P. COLE, T. M. LIN, C. R. LOWE, A. P. MIRRA, B. RAVNIHAR,
E. J. SALBER, V. G. VALAORAS & S. YUASA
“Differences between cases and
controls with respect to frequency of
abortion were observed in only a few
centres and were in the direction which
suggested increased risk associated with
abortion — contrary to the reduction in
risk associated with full-term births.”
4
Epidemiological measures of relative risk
(RR; the relative likelihood of having a given
disease—such as breast cancer—if one has had a
particular exposure—such as induced abortion–
compared to those who have not had the exposure).
If a factor has a:




RR 1.0 – there is no  or  in risk
RR 1.5 – there is a 50%  in risk
RR 2.0 – there is a 100%  in risk
RR 0.5 – there is a 50%  in risk
5
Br. J. Cancer (1981) 43, 72
ORAL CONTRACEPTIVE USE AND EARLY ABORTION AS RISK
FACTORS FOR BREAST CANCER IN YOUNG WOMEN
M. C. PIKE, B. E. HENDERSON, J. T. CASAGRANDE, I. ROSARIO AND G. E. GRAY
From the Department of Family and Preventive Medicine, University of Southern California,
School of Medicine, Los Angeles, California, U.S.A. -- Received 27 August 1980
Accepted 14 October
1980
Summary.— A case-control study was conducted in Los
Angeles County, California, of 163 very young breast-cancer
“A
before the
FFTP,
casesfirst-trimester
(all aged 32 or less at abortion
diagnosis) to investigate
role, if
any, of oral contraceptives
(OC) in
development of
the
whether
spontaneous
ortheinduced,
was
disease. OC use before first full-term pregnancy (FFTP) was
associated
2.4-fold
increase
in
associated with anwith
elevated risk,
which increased
with duration
of OC use (relative risk
~ 2.2
at 6 years of use, P<0.01). This
breast-cancer
risk
(P<0.005).”
increased risk could not be explained by other risk factors. OC
use after FFTP was not associated with any change in risk. A
first-trimester abortion before FFTP, whether spontaneous or
induced, was associated with 2-4-fold increase in breast-cancer
6
risk (P<0.005).
Br. J. Cancer (1982) 45, 327
ORAL CONTRACEPTIVE USE AND ABORTION BEFORE FIRST
TERM PREGNANCY IN RELATION TO BREAST CANCER RISK
M. P. VESSEY, K. McPHERSON, D. YEATES AND R. DOLL
From the Department of Community Medicine and General Practice and the Imperial Cancer Research Fund
Cancer Epidemiology and Clinical Trials Unit, Radcliffe Infirmary, Oxford OX2 6HE
Received 6 November 1981
Accepted 20 November 1981
“TheSummary.—A
results are
entirely
reassuring,”
recent publication from California in this
journal has suggested that both prolonged oral contraceptive
use and abortion before first term pregnancy increase the risk of
breast cancer in young women. Data was presented on 1176
women aged 16-50 years with breast cancer, interviewed in
London or in Oxford, together with a like number of matched
control subjects. The results are entirely reassuring, being, in
fact, more compatible with protective effects than the reverse.
Possible reasons for the differences between the 2 sets of data
are discussed.
“Only a handful
of women…”
7
Journal of the National Cancer Institute, Volume 86, No. 21, Nov. 2, 1994
“Results: Among women who had been
pregnant at least once, the risk of breast
cancer in those who had experienced an
induced abortion was 50% higher than
among other women.”
EDITORIALS
Induced Abortion and Breast Cancer:
More Scientific Data Are Needed
Lynn Rosenberg
“…the overall results as well as
“A
concern,
themajor
particulars
areespecially
far from because
the
observedand
effect
small,tois the
conclusive,
it iswas
difficult
possibility
of reporting
bias.”
see how they
will be informative
to the public.”
But note that the authors invented the term “overreporting”, that breast
cancer patients had imagined abortions that had never taken place!
“Analysis demonstrated … an observed ratio of 22.4 (p
< 0.007) between underreporting of previous induced
abortions among controls relative to overreporting
among cases.”
Also note how those who deny the ABC link still rely on this
Swedish study to support the reporting bias explanation, but
ignore the fact that the preposterous claim of “overreporting”
was retracted in 1998!
The fact is that retrospective studies are relied upon all the time in
epidemiology, with effective safeguards in place. For example,
those who interview the study subjects to collect the data on
reproductive history other variables are blinded as to the status of
the subjects. That is, they do not know, at the time of the interview,
whether they are interviewing a patient or a control.
Moreover, the most well done prospective ABC link study—the
study by Howe, et al. in 1989—reported a significant 90% risk
increase:
Odds ratios (OR) were significantly elevated among
those with an induced abortion (OR=1.9)
Even though the reporting bias hypothesis has
been repeatedly and publicly disproved—as
documented in our meta-analysis—it is still
used routinely to deny the ABC link!
During the past decade, study after study has
been published based on prospective data,
but with such monstrous flaws as to render
their conclusions entirely invalid.
“In 1973, the legal right to an induced
abortion through 12 weeks’ gestation was
established for women with residence in
Denmark … The induced abortions included in
this analysis (were) those occurring between
1973 and 1992”.
“Follow-up for breast cancer for all the women
began on April 1, 1968 or on their 12th birthday,
whichever came later.”
16
British Journal of Cancer (1999) 20(3/4), 600-613
©1999 Cancer Research Campaign
Article no. bjoc.1990.0399
Preterm delivery and risk of breast cancer
M Melbye, J Wohlfahrt, A-MN Andersen, T Westergaard and PK Andersen
Danish Epidemiology Science Centre, Statens Serum Institut, 5 Artiltervej, DK-2300 Copenhagen S, Denmark
18
Table 2 Adjusted relative risk of breast cancer in 474, 158 parous women
According to gestational age at delivery
Gestational
Age (weeks
No of cases
Person-years
(in thousands)
RR (95% CI)
<29
7
9
2.11 (1.00-4.45)
29-31
13
17
2.08 (1.20-3.50)
32-33
11
26
1.12 (0.62-2.04)
34-35
22
58
1.08 (0.71-1.56)
36-37
82
214
1.04 (0.83-1.32)
38-39
350
949
1.02 (0.89-1.17)
40
552
1526
1
>40
326
985
1.03 (0.90-1.18)
*Adjusted for age, calendar period, parity and age at first childbirth.
19
Lancet, March 27, 2004
Breast cancer and abortion: collaborative reanalysis of
data from 53 epidemiological studies, including 83,000
women with breast cancer from 16 countries
Some reasons for eliminating 10 previously
published studies showing an ABC link
1. “Principal investigators…could not be traced”
2.
“original data could not be retrieved by the principal investigators”
3.
“researchers declined to take part in the collaboration”
4. “principal investigators judged their own information on induced
abortion to be unreliable” (even though it had been vetted by peer
review and published in a prominent medical journal).
Journal of Epidemiology and Community Health 1996;50:481-496
481
Induced abortion as an independent risk factor
for breast cancer: a comprehensive review and
meta-analysis
Joel Brind, Vernon M Chinchilli, Walter B Severs, Joan Summy-Long
Department of Natural Science, Baruch College
The City University of New York
17 Lexington Avenue
New York, NY 10010, USA
J Brind
Center for Biostatistics and Epidemiology and
Department of Pharmacology
Pennsylvania State University
The Milton S Hershey Medical Center
Hershey, PA 17033, USA
V M Chinchilli
W B Severs
J Summy-Long
Correspondence to:
Professor J Brind
Accepted for publication
April 1996
We surveyed several thousand early and
mid-career scientists, who are based in the
United States and funded by the National
Institutes of Health (NIH), and asked them
to report their own behaviours. Our findings
reveal a range of questionable practices that
are striking in their breadth and prevalence.
10. Changing the design, methodology or results of a study in response to
25
pressure from a funding source.
NCI Scientific Panel Concludes Abortion Has No Impact on
Breast Cancer Risk Abortion Has No Impact on Breast Cancer
Risk
By Rachael Myers Lowe, cancerpage.com (March 3, 2003) –
A scientific panel of the National Cancer Institute has concluded
there is no connection between abortion and risk of breast cancer;
having had an abortion neither raises nor reduces the risk of
developing breast cancer.
27
Leslie Bernstein, Ph.D., of the Keck School of Medicine at the
University of Southern California, presented the findings. In an
interview with reporters after the advisory board briefing, she said
even though the findings clearly show that “the biggest bang for
the buck is the first birth and the younger you are the better off
you are, ” women should not necessarily make life-altering
decisions based on these findings.
“There are so many other messages we can give women about
lifestyle modification and the impact of lifestyle and risk that I
would never be a proponent of going around and telling them that
having babies is the way to reduce your risk.”
(To listen to Bernstein's remarks, click here.)
“I don’t want the issue relating to induced abortion to breast
cancer risk to be part of mix of the discussion of induced abortion,
its legality, its continued availability. I think it should not be part of
the argument,” Bernstein says. (To hear more of Bernstein's
remarks, click here) http://www.cancerpage.com/news/article.asp?id=5601 28
29
Table 4: Results of logistic regression model for factors associated with
Breast cancer risk.
______________________________________________________________
Factors*
OR (95%CI)
P value
______________________________________________________________
Age (>50) years
2.61 (2.20—3.11)
<0.001
______________________________________________________________
Induced abortion
1.66 (1.30—1.98)
< 0.001
Oral contraceptive use
0.60 (0.48—0.74)
< 0.001
______________________________________________________________
*The significant risk factors in Table 3 with a distribution frequency >10%
including age >50, induced abortion, BMI >25, education >13 years, spontaneous abortion, smoking, breast feeding, oral contraceptive use and nullipars were further evaluated in the multivariate logistic regression analysis.
30
31
32
Asian Pacific J Cancer Prev 2007;8:395-398
33
Am J Pathol 1980:497-512
Biological Facts
Most breast cancers start in Type 1 and
2 lobules
 Breast cancers do not start in Type 3
and 4 lobules
 Induced abortions result in increased
numbers of Type 1 and 2 lobules
 Full-term pregnancies result in
increased numbers of Type 3 and 4
lobules

Types of Breast Lobules
Type 1
Lobule
Type 2
Lobule
Type 3 Lobule
(TDLUs)
10% of all breast
cancers arise in
Type 2 Lobules
(Lobular cancer)
Cancer resistant
when they are the
result of regression
of Type 4 lobules
85% of all breast
cancers arise
Type 1 Lobules
(Ductal cancer)
37
January 2007
38
Breast lobule maturation
before and after first pregnancy
39
The “susceptibility window”

The period between puberty and a full-term
pregnancy

The time the breast is most susceptible to
forming cancer

I.e., when the woman’s breast
is composed primarily of
Type 1 and 2 lobules.
40
The breast maturation process through a
normal full-term pregnancy
By the end of the 1st trimester:

During the maturation of Type 1 lobules
into Type 2, the actual numbers of these
lobules will increase while the surrounding
tissue (stroma) decreases.

The breast now has more
places for cancers to start.
41
The breast maturation process through a
normal full-term pregnancy
By the end of the 3rd trimester:


The breast is now:

85% Type 4 lobules

15% immature cancer
susceptible lobules
There are now fewer places for
cancer to start.
42
J. KUNZ
and
P.J. KELLER
Department of Gynaecology and
Obstetrics,
University of Zurich, Switzerland
British Journal of Obstetrics and
Gynaecology
August 1976. Vol 83
pp 640-644
43
Journal of the National Cancer Institute, Volume 86, No. 21, Nov. 2, 1994
“Results: Among women who had been
pregnant at least once, the risk of breast
cancer in those who had experienced an
induced abortion was 50% higher than
among other women.”
45
Journal of the National Cancer Institute, Volume 86, No. 21, Nov. 2, 1994
46
Conclusions
At least three causal connections between
induced abortion and breast cancer incidence
have been well established by over 50 years of
published epidemiological evidence, supported
by every other line of published biological and
medical evidence. Such evidence has resulted in
a very detailed understanding of the role of
pregnancy in normal breast development and the
development of cancer.
The three connections are:
1. Termination of the pregnancy before 32 weeks
gestation deprives a woman of the risk-lowering
effect of full-term pregnancy.
2. The burst of growth stimulation during the
pregnancy before it is terminated leaves a postabortive woman with more places for cancer to start.
3. Abortion leaves a woman with a higher risk of very
premature delivery (before 32 weeks) in subsequent
pregnancies, which increases risk in the same way
as induced abortion.
A 4th connection may also be added: The risk lowering
effect of breastfeeding, which cannot occur after a
pregnancy terminated by abortion.
48
Conclusions (cont’d)
The cover-up of the abortion-breast cancer link (ABC
Link) has also been well established by the published
evidence for over 25 years, which has accelerated
over the past decade.
Since 1997, a continuing stream of publications in
prestigious medical and epidemiological journals,
issuing from prestigious research institutions and supported by the highest government agencies such as
theNational Cancer Institute and voluntary institutions
such as the American Cancer Society, has embodied
junk science at its worst: Deliberate conflation of
induced and spontaneous abortion, which are physiologically different events, mischaracterization of the
published record, the statement of outright falsehoods,
And all manner of illicit data manipulation have been
49
documented in medical and scientific journals.
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