A European study published in the fall issue of The Journal of American Physicians and Surgeons states that abortion is the "best predictor" of breast cancer, and calls the current widespread incidence of breast cancer "epidemic," stated the National Catholic Register of 11/18/07. 

The study is based on data collected in England, Wales, Scotland, Ireland, Sweden, the Czech Republic, Finland, and Denmark.  The study made special note of the fact that such detailed, reliable data is not available in the U.S., asserting that "official abortion statistics in the United States and France are known to understate the numbers of legal induced abortions."  (my emphasis)

The forecast for the increase in breast cancer in the eight countries studied are considerable. In England and Wales, for example, instances of breast cancer are expected to increase from 39,229 reported in 2004 to more than 65,000 in 2025, and increase of more than 66%. (NCR 11/18/07)

This post is a response to another poster who is interested in dialoguing about the abortion-breast cancer link.  I am quite interested in these phenomena as well, and I state up front that I am totally against abortion.

I realize that the National Cancer Institute in America has stated that abortion causes no increased risk for abortion.   I believe that studies done as the one above and other recent ones which show an increase in breast cancer (40%) in women in China since implementing the one-child policy, relying heavily on abortion, show the opposite. Also, Ireland, and Poland, which restrict abortions greatly compared to the U.S., have fewer cases of breast cancer. I am prepared to discuss these studies in some detail.

Why does an abortion leave a woman more at risk for breast cancer?  At puberty, when estrogen levels rise, the breast forms Type 2 lobules. It is only through the hormonal environment and length of a full term (or to at least 32 weeks) pregnancy that there is full maturation of Type 3 and 4 lobules in the breast. This maturation protects a woman and lowers her risk of breast cancer.

This is why women who undergo full term pregnancies have lower risk of breast cancer and why women who remain childless have higher risk of breast cancer. Women who give birth after age 30 are also at increased risk of breast cancer as their immature Type 1 and 2 lobules are exposed to estrogen for the many years between the time of their first menstruation until their first full term pregnancy. Abortion in women under 18 and over 30 years old carries the greatest risk: these women have the highest percentage of Type 1 lobules in their breasts.

It is the interplay of these two principles, estrogen exposure and breast lobule maturation, which accounts for the fact that abortion can lead to breast cancer. Within a few days of conception, a woman's estrogen level rises. By the end of the first trimester, estrogen levels have increased by 2000%. The estrogen stimulation that causes the multiplication of Type 1 and 2 lobules, results in sore and tender breasts early on in pregnancy. It is only after 32 weeks that a woman's breasts stop growing larger and mature into Type 3 and 4 lobules in preparation for breast-feeding.

If abortion ends a woman's pregnancy before full maturation of her breasts, she is left with an increased number of the immature Type 1 and 2 lobules. She now has a greater number of the breast lobules where cancers can arise. This causes her to be at greater risk for breast cancer. It is through this same biologic mechanism that any premature birth before 32 weeks more than doubles breast cancer risk.

Induced abortion thus increases breast cancer risk by two mechanisms. First, abortion leaves the breast with increased numbers of Type 1 and Type 2 lobules, those lobules in which cancer cells are formed, which are then exposed to more estrogen through menstrual cycles. These lobules would otherwise have been protected from cancer by maturation to Type 3 and 4 lobules, if pregnancy had gone to term. Second, the breast is exposed to high levels of estrogen during pregnancy, which can induce cancer cells to form. 6
http://www.bcpinstitute.org...

I do agree that this is a highly politicized issue. People on both sides of the abortion issue do not want to give any ground. But in my opinion, a woman’s health is more important than abortion politics.  According to the Alan Guttmacher Institute at www.guttmacher.org/pubs/journals/3711005.pdf,  86% of abortions done in America in 2004 were for social reasons, such as starting a new job, or being a college student- not for the life of the mother.

 I think women should be informed of the risks of abortion and breast cancer, especially when breast cancer runs in the family.

If anyone is interested in discussing this issue, I would be pleased to do so.