The Nurses Health Study, one of the largest health studies of
women ever conducted, has shown that diabetic women are 17% more
likely to develop breast cancer than those who don’t have
diabetes. The link was found among postmenopausal women but not
premenopausal women.

This is yet another reason to keep your insulin and blood sugar
under control.

Source: Diabetes Care, 2003; 26:1752-1758