BRCA2 and ovarian cancer: (Neff et al., 2017) Antoniou et al. (2003) compared the data from four different studies conducted in the United States, Canada, Israel and Poland for ovarian cancer and found the average cumulative risks of developing ovarian cancer by age of 70 years was almost 39% of BRCA1 mutation carriers and 11% of BRCA2 mutation carriers.