The U.S. rate was 36.3%, far outpacing the number of preventive surgeries performed by the majority of other countries Narod studied, including France and Canada.

CNN: Why more women are choosing double mastectomies

In a global study conducted by Dr. Steven Narod, senior scientist at Women's College Research Institute in Toronto, the United States had the highest rate of prophylactic mastectomy in BRCA1 and BRCA2 mutation carriers.

CNN: Why more women are choosing double mastectomies