Don’t believe rumors that antiperspirants and deodorants cause breast cancer. Most good studies over the years have not found a link.
One concern has been that paraben preservatives in antiperspirants and deodorants could migrate into breast tissue and cause cancer. However, a new English study published in the Journal of Applied Toxicology found that antiperspirant and deodorant users and women who never used these products had similar levels of paraben residues in their breast tissue.
Parabens are added to many cosmetic, pharmaceutical and food products, and have been detected in nearly all human blood and urine samples. It’s thought that parabens may increase cancer risk because of their weak estrogenic activity, but so far there has been no convincing evidence to support this claim.