Those following daily are beginning to get confortable with the jargon (I hope). For ease of newcomers following along , please consult the glossary of terms that I’ve written to make the terminology very understandable.
Title: ABORTION AND THE RISK OF BREAST CANCER: A CASE-CONTROL STUDY IN GREECE
(The discerning reader will recognize Trichopoulos as one of the authors in yesterday’s paper #2. This group is from Harvard University, Greece, and Sweden}
Authors: Loren Lipworth, Klea Katsouyanni, Anders Ekbom, Dimitrios Trichopoulos
Journal: International Journal of Cancer, 1995, 61:181-184
This study was a case-control study.
820 patients with confirmed breast cancer (BC) {The cases}.
795 orthopedic patients and 753 healthy visitors {The controls}.
The odds ratios (relative risks) were reported with 95% confidence intervals (CI).
It should be noted that the authors discuss in the introduction the controversy surrounding purported recall bias, and say the following of their subjects, all of whom reside in Greece:
“Even before their legalization, induced abortions were practiced in Greece with widespread social acceptance. Although no validation has ever been undertaken in Greece, it is of interest that a study of induced abortion in relation to ectopic pregnancy and secondary infertility (Tzonou et al, 1993) has demonstrated associations similar to those expected on the basis of the collective published evidence regarding these diseases, that is, no significant association with ectopic pregnancy and a weak positive association with respect to secondary infertility. This can be interpreted as indicating that healthy women in Greece report reliably on their history of induced abortion.”
This is an important observation, because it is the claim of ardent pro-abort researchers such as Palmer and Rosenberg that recall bias manifests in healthy controls underreporting their prior abortions, thereby producing an appearance of increased risk in breast cancer patients who’ve had induced abortions.
Results:
The Odds Ratios (OR’s) are essentially the same as relative risk (RR).
The OR in breast cancer patients who had abortions matched to controls matched for age, parity status, age at first birth, menopausal status, Quetelet’s index, and alcohol intake were as follows:
Spontaneous abortion (miscarriage)- 0.97 (essentially no increased risk)
Induced abortion- 1.51 (51% increased risk)
Spontaneous and/or induced abortion- 1.38 (38% increased risk)
Among nulliparous women, there was no difference in breast cancer rates between nulliparous women who had abortions and those who did not. Among parous women, there was an OR of 1.76 (76% increased risk of BC) in parous women who had abortions compared to parous women who didn’t.
Finally, the most bracing result was in parous women who had abortion prior to First Full Term Pregnancy (FFTP) using nulliparous women as a control:
Induced abortion before FFTP. OR=2.06 (more than double the risk)
Induced abortion after FFTP. OR=1.59 (59% increased risk)
Discussion: The authors state,
“It appears, therefore, that the most important confounding bias (recall bias) was adequately controlled. Information bias with respect to induced abortion was is certainly possible, but not likely to be large in this study, given the permissive social environment with respect to induced abortion in Greece and the fact that the interviews were conducted in the hospital setting by hospital-associated health professionals…
“Thus an appropriate interpretation of these results, and to a considerable extent of the collective epidemiological evidence might be that an interrupted pregnancy does not impart the long term protection of a full term pregnancy attributable to terminal differentiation, whereas it may impart a small and occasionally demonstrable elevation of breast cancer risk on account of the transiently increased stimulation by estrogen.
“The higher excess risk associated with an abortion before rather than after first birth, noted in the present study, is compatible with the experimental evidence that terminal differentiation {conversion of cancer-prone Type 1 and 2 cells to cancer resistant Type 4 cells} depends on the occurrence of a full term pregnancy.”
The study was supported by European and Greek grants. Interesting to note as we go along the lack of spin in grants not given by the US National Cancer Institute, where Dr. Louise Brinton is head of epidemiology.
This October, please consider $upporting the following who desperately need our $upport to get the truth out*:
Breast Cancer Prevention Institute
Coalition on Abortion/Breast Cancer
*I have no institutional affiliation or membership with either group. Karen Malec and BCPI have been great resources for me, utterly generous with their time and resources.
1995. 1995? 15 years ago. Shall I even start on the misconstrued outcomes you have derived from the report? What were the different rates of factors such as smoking and drinking between women who had abortions and those who hadn’t?
Cranium,
In the post I discuss the factors for which control subjects and BC subjects were matched, including age and alcohol consumption. The study withstands scrutiny as it was conducted contemporaneously with many others who established similar RR’s but tried to invent a phenomenon (recall bias) in order to attenuate the impact of abortion on women’s health, and for which they had absolutely NO empiric data. It was wishful thinking, a flight of fancy.
The strength of this study is that the authors controlled for the one variable held out as the explanation for the increased risk of BC in post-abortive women: Greece was extremely permissive with abortion for years before it became legal. In all papers, the BC subjects and controls were carefully matched for known variables, and these were not contentious issues as you would now suggest.
I’ve only just begun and have not even scratched the surface. As the readers follow along, we will descend gradually into the depths of the literature.
I should say that while I always believed intuitively that abortion was wrong, I actually felt no affinity for the pro-life movement for years because of its extreme portrayal in the media. My reading of the scientific literature and what it had to say caused me to realize the enormous propaganda and denial of truth that the pro-choice community was engaging in in order to sustain its agenda. Ultimately it wasn’t my Catholic Christian faith that compelled me to speak out, but my scientific integrity.
As a Catholic, I’m a bit ashamed of that order of operations. But then, it ultimately works to the good of witnessing the truth, the scientific truth which validates the truths of Catholic Christian anthropology.
I still see gaping holes in the evidential comparisons in that there is a distinct lack of diminution for a wide variety of potential impacting factors.
Good luck with your journey, it’s going to be steep and bumpy.
Cranium,
The data tables for all of the variables are contained within the papers, and I give the complete reference to each paper cited. I’m hitting the highlights, but NONE of the authors claims to have failed in accounting for all known BC variables and properly matching cases and controls, which is why the control pools are so much larger than the case pools. Have your local library get copies of the papers for you if you don’t have access to a medical library.
Gerry:
Importantly, Karen Michels was also a co-author in the study, Lipworth et al. 1995. Professor Joel Brind explained how the authors found no evidence of response bias, but later told a New York Times scientist/reporter that response bias is a flaw in the study. Brind said during a 1999 lecture in Malvern, Australia,
“…they claim their finding was not attributable to response bias. Interesting that this study was submitted for publication on October 20th 1994, exactly one week before October 27th 1994, when Harvard epidemiologist Karen Michels told Dr. Lawrence Altman, epidemiologist reporter of the New York Times, that ‘that is a flaw in the design because women who have breast cancer are more likely to disclose an abortion than women who did not develop breast cancer.'” Brind said, sarcastically, “You see it’s a fact. Everybody knows it. Who should that Karen Michels be but the same one who is on the by-line of the study in Greece: Karen B Michels! What a difference a week makes in one’s interpretation of whether it’s response bias or not.”
Significantly, Michels served as lead author in a 2007 study, “Induced and Spontaneous Abortion and Incidence of Breast Cancer Among Young Women.” Arch Int Med 2007;167:814-820.
Brind authored an article citing serious flaws in Michels’ team’s paper. It’s available here:
Brind J. Induced Abortion and Breast Cancer Risk: A Critical Analysis of the Report of the Harvard Nurses Study II. Journal of American Physicians and Surgeons (Summer 2007) Vol. 12, No. 2, p. 38-39. Available at: .
The flaws in the study, Michels et al. 2007, include fundamental violations of the scientific method:
1) Insufficient follow-up time between exposure to abortion and the development of breast cancer;
2) Exclusion of in situ breast cancers, which develop earlier than do invasive breast cancers;
3) Misrepresentation of the published record concerning reporting bias; Even Michels’ earlier 1995 research found no evidence of reporting bias; and
4) Failure to adjust for confounding factors.