I recently found out that my mother has breast cancer. I have been doing a ton of research on the internet. I recently found this issue of anti-perspirants vs. deodarants on the healthlinkusa.com "ask the mayo physician" site. The Mayo clinic said it is an unfounded health myth that anti-perspirants cause breast cancer. Look into this section of healthlink usa to read the documentation yourself and feel a little more relaxed. Good luck.