Very interesting. Let me bring in a couple of quotes.
TWO WAYS THAT ABORTION RAISES BREAST CANCER RISK
There are two ways that abortion raises a woman’s risk for breast cancer. The first way is not debated. It’s called the "protective effect of childbearing," and scientists have acknowledged this effect for centuries. The second way is debated, and scientists have studied this effect - known as the "independent link" - since 1957. It has to do with this question: Does an abortion leave a woman with more cancer-vulnerable breast tissue than she had before she became pregnant?
First Way - Loss of the Protective Effect of Childbearing: Delayed First Term Pregnancy, Childlessness, Fewer Births, Decreased Breastfeeding
Scientists first observed in the 17th century that women’s reproductive histories impacted their risk for breast cancer when it was noticed that nuns were at high risk for the disease. Scientists surmised that childbearing provides women with increased protection.
Today’s medical experts agree that the best way women can reduce their lifetime risk for breast cancer is by: 1) Having an early first full term pregnancy (FFTP) starting before age 24; 2) Bearing more children; and 3) Breastfeeding for a longer lifetime duration. It’s undeniable that abortion causes women to change their childbearing patterns. It leads them to forego the protective effects of early FFTP, increased childbearing and breastfeeding. Consequently, scientists do not debate that it increases breast cancer risk in this first of two ways.
I recall from La Leche League sources that I became aware of years ago that longer term breast-feeding does reduce the risk of breast cancer. As I recall, women who breast feed even one child for six months or more, especially if it is the sole or primary source of nutrition for the child, have lower cancer rates than women who breast-feed for only a few days or weeks.
The link above later notes:
Scientists have long considered breastfeeding a likely protective factor, but this wasn’t confirmed until recently. In July 2002, a large meta-analysis of 47 epidemiological studies conducted in 30 countries and published in the British medical journal, Lancet, determined that women can reduce their relative risk of the disease by 4.3% for every 12 months of breastfeeding and 7.0% for each birth. It was concluded that skyrocketing breast cancer rates in the developed nations could be reduced by more than one-half if only women would bear more children and breastfeed for longer duration. [Beral, V (July 20, 2002) Lancet 360:187-95]
The second link:
Abortion has been implicated with breast cancer in yet another way, however, and estrogen overexposure is the explanation for it. There is staggering evidence of an independent link between abortion and breast cancer. What this means is that a woman who has an abortion is left with more cancer-vulnerable cells than she had before she ever became pregnant. Biological evidence and more than two dozen studies worldwide support a cause and effect relationship. Fifteen studies were conducted on American women, and 13 of them reported risk elevations. Seven found a more than a twofold elevation in risk. Seventeen are statistically significant, 16 of which demonstrated a positive association. The term “statistical significance� means that scientists are at least 95% certain that their findings are not due to chance or error.
The evidence of a causal relationship between abortion and breast cancer isn’t only based on a statistical relationship either. Scientists also require biological evidence and a reasonable biological explanation before concluding that there’s a causal relationship. These requirements have been met.
Biological Evidence
Researchers were able to demonstrate that 77.7% of a group of rats given abortions could be caused to develop breast cancers with the carcinogen DMBA. On the other hand, 0% of the rats allowed to have a full term pregnancy, but not allowed to nurse their pups, developed tumors when exposed to DMBA. Among a group of 9 rats allowed to have a full term pregnancy and nurse their pups, only one developed a tumor. Among two groups of virgin rats, 66.7% and 71.4% developed tumors after being exposed to the carcinogen. Rats with abortion histories were at the greatest risk of all 5 groups. The experiment demonstrated that an induced abortion resulted in close to a 80% risk elevation among rats. [Russo J, Russo IH (1980) Am J Pathol 100:497-512]
I have to say, except for the breast-feeding, this is all new to me.
" . . . the line separating good and evil passes, not through states, nor between classes, nor between political parties either, but right through every human heart . . . ." Alexander Solzhenitsyn