About 5 percent of women with breast cancer have a hereditary form of this disease. Specific alterations in certain genes, such as those in the breast cancer genes BRCA1 or BRCA2, make women more susceptible to breast cancer. Women age 45 or older who have at least 75 percent dense tissue on a mammogram are at elevated risk. Women who received chest irradiation for conditions such as Hodgkin's disease at age 30 or younger are at higher risk for breast cancer throughout their lives and require regular monitoring for breast cancer. A woman who has her first child at age 30 or older has an increased risk of breast cancer.
Age is the most important factor in the risk for breast cancer.
The older a woman is, the greater her chance of getting breast cancer. No woman should consider herself too old to need regular screening mammograms. A woman's chance. . . 1 out of 2,525 by age 40. . . 1 out of 217 by age 50. . .