There are more than 3.1 million women with a history of breast cancer in the U.S. This includes women currently being treated and women who have finished treatment.
Breast cancer incidence rates in the U.S. began decreasing in the year 2000, after increasing for the previous two decades. They dropped by 7% from 2002 to 2003 alone. One theory is that this decrease was partially due to the reduced use of hormone replacement therapy (HRT) by women after the results of a large study called the Women’s Health Initiative were published in 2002. These results suggested a connection between HRT and increased breast cancer risk.
About 5-10% of breast cancers can be linked to gene mutations (abnormal changes) inherited from one’s mother or father. Mutations of the BRCA1 and BRCA2 genes are the most common. On average, women with a BRCA1 mutation have a 55-65% lifetime risk of developing breast cancer. For women with a BRCA2 mutation, the risk is 45%. Breast cancer that is positive for the BRCA1 or BRCA2 mutations tends to develop more often in younger women. An increased ovarian cancer risk is also associated with these genetic mutations. In men, BRCA2 mutations are associated with a lifetime breast cancer risk of about 6.8%; BRCA1 mutations are a less frequent cause of breast cancer in men.