Q: As each year passes, I seem to know more and more women with breast cancer. What is the chance that I will develop breast cancer myself?A: Breast cancer is the most common cancer in US women and is greatly feared. However, many women overestimate their risk. One widely quoted statistic--"one in nine"--refers to the cumulative lifetime risk of breast cancer for a woman who lives past the age of 85. The risk of breast cancer for a woman in any given year or decade of her life is much lower than one in nine. The chance a woman will develop breast cancer in the next 10 years is one in 250 for a 30-year-old woman, one in 77 for a 40-year-old woman, one in 43 for a 50-year-old woman, and one in 38 for a 60-year-old woman. Some subgroups of women have higher than average risk. Factors that increase an individual woman's chance of developing breast cancer include older age, previous breast cancer, relatives with breast cancer (especially if mother, sister or daughter is affected, or if cancer was found before menopause), previous breast biopsies (especially if precancerous tissue was found), previous uterine or ovarian cancer, past radiation treatment to the chest, having a first pregnancy after 30, having no children, having an early first period (before age 12), having a late menopause (after age 55), postmenopausal obesity, and moderate alcohol intake. Current birth control pill use raises breast cancer risk slightly. Many (but not all) studies suggest that long-term (more than 5 years) hormone replacement may slightly increase breast cancer risk.