Hereditary breast and ovarian cancer

Breast cancer is a major disease affecting women in industrialized countries, for whom the lifetime risk exceeds 10%. In the US, breast cancer affects one in eight women.1 Ovarian cancer is substantially less common than breast cancer, with a lifetime risk of 1.6% for women in industrialized countries2; however, it is one of the most lethal gynecological malignancies. It is estimated that 5%–10% of breast and invasive ovarian cancer cases are hereditary and attributable to mutations in several highly penetrant susceptibility genes.3,4 Inherited susceptibility has already been recognized as a significant risk factor for cancers of the breast and female genital organs.