Screening all women over 30 years age for breast and ovarian cancer gene mutations can be cost effective and could also prevent more of these cancers than just screening those at genetic high-risk, suggests a study led by an Indian-origin researcher. The most well-known breast and ovarian cancer causing genes are BRCA1 and BRCA2, and women carrying either of the gene mutation have approximately a 17-44 per cent chance of developing ovarian cancer and a 69-72 per cent chance of developing breast cancer over their lifetime.