BRCA1 is also associated with the predisposition to ovarian cancer. BRCA2 is believed to be equal in importance to the BRCA1 gene. There are however, differences in these genes. The high incidence of ovarian cancer-linked to the BRCA1 gene, but the BRCA2 gene is associated with very low incidence of ovarian cancer. No male breast cancer cases have been seen in the BRCA1 family sets, whereas several cases are present in the BRCA2 families.
Breast cancer is far the most frequently diagnosed neoplasm in women.
Each year, over 186,000 new cases and 46,000 death are reported in the United states alone. A number of risk factors for the development of breast cancer have been identified. Non-genetic risk factors include age of menarche, menopause, and first child birth. Early parity and menopause appears to decrease risk, while early menarche correlates with an increased risk. Risk is also found to increase with a positive breast cancer family history, presumable due a genetics factors.