Many patients ask me if sunscreens can cause cancer.  My answer is that there is much more evidence that sun exposure causes cancer than that sunscreen causes cancer. Read more at 

In addition, I always use the example of Sweet and Low sugar substitute being declared to cause cancer. 

If a study is done on mice and 1000 times as much of a chemical than can possibly be consumed by a person is given to those mice, you can't then conclude that the chemical will cause cancer in humans just because that huge amount of chemical caused cancer in the mice. 

The American Academy of Dermatology still recommends sun protection via sunscreen and/or clothing.  The higher the SPF the better, and re-apply every 2 hours, as the sunscreen eventually wears off.