The older a woman is, the more likely she is to get breast cancer.

Women who give birth to their first child at later ages are at increased risk of breast cancer compared to women who have their first child at younger ages. For example, women who give birth for the first time after age 35 are about 40 percent more likely to get breast cancer than women who have their first child before age 20.

Women who began their periods before age 12 have about a 20% higher breast cancer risk compared to those who began their periods after age 14.

Going through menopause at a later age increases the risk of breast cancer. For example, studies show that women who go through menopause after age 55 have about a 30% higher risk of breast cancer than women who do so before age 45.

Alcohol can change the way a woman’s body metabolizes estrogen (how estrogen works in the body). This can cause blood estrogen levels to rise.

Current or recent use of birth control pills (oral contraceptives) slightly increases the risk of breast cancer (This extra risk, though, is quite small because the risk of breast cancer for most young women is low).

Many studies link Body Mass Index (BMI) to breast cancer risk. However, BMI affects risk differently before and after menopause. Before menopause, being overweight or obese modestly decreases breast cancer risk, After menopause, being overweight or obese increases breast cancer risk.

Breast density: Women with high breast density are four to five times more likely to get breast cancer than women with low breast density. Breast density is not a measure of how the breasts feel, but rather how the breasts look on a mammogram. High breast density means there is a greater amount of breast and connective tissue compared to fat.

Family history of breast, ovarian or prostate cancer: A woman who has one first-degree female relative with breast cancer has almost twice the risk of a woman without a family history. If she has more than one first-degree female relative with a history of breast cancer, her risk is about three to four times higher.

If you are considering taking Menopause Hormone Therapy MHT (estrogen plus progestin or estrogen alone), discuss the risks and benefits with your doctor. For short-term relief of menopausal symptoms, estrogen plus progestin is an approved MHT. However, the FDA recommends that it be used only at the lowest doses for the shortest time possible.Estrogen plus progestin increases the risk of both developing and dying from breast cancer. When women take these hormones, their risk of having an abnormal mammogram increases within the first year of use. And, their risk of breast cancer increases within the first five years of use.

White and now African-American women have the highest incidence (rate of new breast cancer cases) overall. However, there are differences when looking at these rates by age. Among women over 60, white women have higher rates of breast cancer compared to African-American women. Among women younger than 45, African-American women have higher rates of breast cancer. The reasons behind these differences are under study. They may include differences in prevalence rates of some reproductive and lifestyle factors related to breast cancer risk as well as differences in tumor biology. Triple negative breast cancers (which have a poorer prognosis) are more common among African-American women than among women of other ethnicities.