Why Is the Anti-Abortionists Doing This (Abortion and Breast Cancer)

Great Debates
1

I came across this article in my morning newspaper. To sum up, anti-abortion groups are now buying billboard space saying, among other things, that abortion causes breast cancer. The problem is, according to the National Cancer Institute and and the American Cancer Society, it doesn’t.

I consider abortion morally wrong, and I would be happy to see a day when it never happens. These tactics won’t make that happen. Don’t people understand that tactics like cruelty and lying make some of us more resistant to their position? Yes, I realize not all Pro-Life people approve of these actions. I also know a lot of animal lovers, including me, who can’t stand PETA either. The problem is, actions like this polarize people rather than bringing them together.

I know we have some Pro-Life people on this board. Please, I would like to hear your thoughts on this article. Do the ends really justify the means? If so, would you please explain it to me.

Respectfully,
CJ

2

When did they determine that it doesn’t?

I’ve read two newspaper articles that both say that abortion increases the risk of breast cancer. While I don’t believe everything I read in the newspaper (the same one that reported the guy who “rode the tower down and survived!”), I had been lead to believe that this was factual - even by a doctor.

3

IIRC, a small study or two several years ago suggested that there might be a statistical link. There is also a theoretical reason for a correlation–one risk factor for breast cancer is lifetime exposure to estrogen, which is reduced in pregnancy, so a woman who terminates her pregnancy will be exposed to more estrogen than one who carries to term. (However, by the same reasoning, she would be at a decreased risk over someone who never got pregnant at all.) There has also been speculation that the abrupt hormonal chances of pregnancy and termination result in changes to the breast tissue that may lead to cancer.

Later review found those early studies to be flawed, mostly due to reporting bias. Further, larger, better studies have been done since then, nearly all of which have found no statistical link between the two. Of course, you can never say anything very conclusively in medicine, but ultimately there is no reason to think that the above factors lead to a statistically significantly increased risk of breast cancer.

This hasn’t stopped pro-lifers from shouting “abortion causes breast cancer!” from the rooftops, or from trying to get legislation passed requiring doctors to inform their patients of this before performing an abortion. It’s a dishonest tactic, but there is enough wiggle room in the science to keep it from being outright fraud.

Dr. J

4

Their reasoning is absolutely crackers, because logically they are saying that pregnancy is a good way to reduce the risk of breast cancer. There goes the abstinence argument! There goes the birth control argument! Get pregnant, and be sure not to have an abortion once you do.

5

IIRC, the doctors who conducted the first study DoctorJ cited later proved to be anti-abortion and allowed that bias to carry into their research.

Robin

6

A large number of studies have looked at this question. A few found a modest increase in breast cancer risk related to abortion. Others found no such link, or even a small decrease in risk for patients who had an abortion compared to those who carried a pregnancy to term. Therefore, mainstream researchers have concluded to this point that there is no significant evidence that abortion increases the risk of breast cancer.

One way to check out the studies is to do a PubMed search (free online) of the scientific literature looking for reviews on the subject.

If anti-abortion rights groups want to be taken seriously regarding their stated concerns for maternal health, they’ll cease using this particular dishonest scare tactic and/or denounce those who do.

7

To answer the eternal question (Cite???) I found this abstract from a recent review article on the subject:

1: Obstet Gynecol Surv 1998 Nov;53(11):708-714.
The alleged association between induced abortion and risk of breast cancer: biology or bias?

Bartholomew LL, Grimes DA.

Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, USA.

“Many case-control studies have addressed this question, but their results have been inconsistent…Two recent, large cohort studies, which are less susceptible to bias, showed either protection or no effect on breast cancer risk from an induced abortion. At present, level II-2 evidence (cohort and case-control studies) supports a class B recommendation (fair evidence) that induced abortion does not increase a woman’s risk of breast cancer later in life.”

8

Cite, please?

The allegation isn’t that pregnancy itself reduces the risk of cancer. Rather, the allegation is that the interruption of pregnancy increases this risk. The two claims are quite different, as anyone can see.

As for the claim that the correlation has been disproven… I think that claim is itself overblown. See http://www.abortioncancer.com/denmark.htm

9

I wish I had time to do a point-by-point deconstruction of the above site (from JThunder’s post) but I have to leave here in 15 minutes. Maybe later tonight. But, from the first page onwards, I believe that it is fatally flawed from a huge bias – he states that induced abortion is the #1 preventable risk factor for breast cancer, which I don’t believe at all.

JThunder’s linked page criticizes one NEJM article. Even if that is flawed, it is just one piece of a puzzle with lots of evidence besides that one article. The data are pretty clear that there is not a major impact, if there is an impact at all on induced abortion and pregnancy.

Breast cancer and the reproductive cycle is a complex thing. Age at menarche, age of first pregnancy, number of pregnancies, and a litany of other factors have repeatedly been shown across many studies . Most studies have shown no significant increase in risk for induced abortion and breast cancer. A nice prediction is that we would expect is corresponsding increases in breast cancer risk for people who have had 3 versus 2 versus 1 versus 0 induced abortions. Another piece of the puzzle answers this pretty nicely:

Sanderson M, Shu XO, Jin F, Dai Q, Wen W, Hua Y, Gao YT, Zheng W. “Abortion history and breast cancer risk: results from the Shanghai Breast Cancer Study.” Int J Cancer 2001 Jun 15;92(6):899-905.

This study is a large cohort study of women in Shanghai, where induced abortion is an accepted part of family planning. They show no increase in breast cancer risk, even in women who have had 3 abortions.

Other studies are similar, and have found similar things. Just because one article may or may not be flawed (I haven’t read it, but plan to later tonight) does not invalidate the whole argument.

For those novices at using Pubmed, I would suggest a search term of induced abortion AND cancer AND review[pt] to get started – this will bring up only reviews of the issue. Otherwise, you will have to sort through hundreds. Although you may like that sort of thing.

10

Wooo! Fargo! I’m famous!

I have nothing else to contribute.

11

Back off; I merely misread DoctorJ’s explanation. My post was wrong because I misread it.

Make that “The two claims are quite different, as anyone except one person, Cranky, can see.”

12

I don’t think you misread my explanation at all, Cranky. Nulliparity is a risk factor for breast cancer, so it would make sense to say that getting pregnant reduces one’s risk of breast cancer. (The reduction is not large–remember that most women who get breast cancer have no particular risk factors aside from age.) This is one theoretical explanation I have heard to support a link between abortion and breast cancer, but as you point out, it isn’t a very good one.

Other mechanisms have been postulated, but the bottom line is that the statistics just don’t show an increased risk. Even if there are a dozen perfectly logical ways in which induced abortion could possibly increase the risk of breast cancer, it doesn’t matter, because it doesn’t do so.

Dr. J