I'm sorry to say the medical literature I find don't support this statement. (And linking to a poster's bare statement is not the same as citing the specific research or article supporting the claim.)
"Pre Milk" is also called colostrum, which starts being produced during the second trimester of pregnancy (week 13 to week 28). Searching PubMed for articles on cancer and colostrum, I don't find any in the first 3 pages saying that colostrum contributes to cancer. I find some suggesting the opposite: Curr Protein Pept Sci. 2009 Aug;10(4):308-38. Molecular and biotechnological advances in milk proteins in relation to human health.
Limiting the search to colostrum and breast cancer, I find 13 articles, none of which conclude that colostrum contributes to breast cancer.
If you have scientific support for this statement, I'd like to see it.
All I know is that the link between breast cancer and abortion has been covered up.
Really? You can't find anything regarding the proven link between abortion and breast cancer?
I wish I had links at my fingertips but don’t, but here is my recollection on the topic.
The connection between abortions and breast cancer is real; it is increased the earlier a woman has had an abortion, as well as the number. Also it is increased if a woman had an abortion before carrying a pregnancy to term. From what I remember, because the breasts undergo hormonal changes very early in the pregnancy, the abortion, unlike a nature-caused miscarriage, which are not allowed to continue normally. The hormonal changes involve increase in breast tissue including growth of the milk ducts or glands, and when abruptly stopped in an abortion, can cause cancer. I do not remember exact mechanisms involved.
Feminists and pro-abortion people really, really hate these studies and bury them as much as they can.