Breastfeeding can reduce the incidence of dozens of different types of cancers in the child, all the way into the breastfed child's adulthood!!!!
Here's a good link from KellyMom that has many articles on these protections. http://kellymom.com/pregnancy/bf-prep/bf-benefits/
Prevention of leukemia: http://www.berkeley.edu/news/media/releases/2004/10/26_breastfeeding.shtml
Cancer preventing agents found in colostrum and mature milk and NOT found in formula: Result: Breastfeeding reduces the incidence of MANY cancers in breastfed children: (Not "may" IT DOES!) http://www.infantrisk.com/content/breastfeeding-may-protect-infants-against-cancers
Here's some data in this list of 101 Reasons to Breastfeed http://www.notmilk.com/101.html
There are scores more studies.
Also, La Leche League has Professional Liaison leaders who can help you. I've testified in several custody cases based on these very articles. You can contact LLL to find a Professional Liaison Leader in your area who is knowledgeable in these matters. It's almost always better to have a professional, a Lactation Consultant or a LLL Pro Liaison Leader testify for you, than to present the evidence yourself, make sure your lawyer knows this stuff, too.
Edited by MaggieLC - 12/17/13 at 2:07pm