Clinical guidance

Breast Cancer Q&A

Published October 10, 2023

woman in robe doing a breast exam

In the United States, breast cancer is the most common cancer in women and other people assigned female sex at birth, except for skin cancer. The good news is there are steps you can take to prevent and detect breast cancer.

What is breast cancer?

Breast cancer is a group of abnormal cells in the breast that grow and hurt healthy cells. It can happen in one or both breasts and can spread to other parts of the body.

What causes breast cancer?

We don’t know for sure, but you’re at higher risk for it if you:

  • Are a woman or were assigned female sex at birth
  • Are Caucasian
  • Are 55 years or older
  • Have a family history of breast or ovarian cancer
  • Have certain problems with your genes
  • Had your first menstrual period before age 12 or went through menopause after age 55
  • Have dense breasts

People also tend to be at higher risk for breast cancer if they:

  • Don't get much physical activity
  • Eat a diet high in saturated fats without many fruits and vegetables
  • Use tobacco products, like cigarettes
  • Regularly drink a lot of alcohol
  • Are at a much higher weight than recommended
  • Take combined hormonal replacement therapy (HRT) for menopause

How can I get tested for breast cancer?

The best way to screen (test) for breast cancer is with a mammogram. Mammograms are x-rays of the breast tissue that can detect cancer and other problems.

Women and other people assigned female sex at birth who are 40 and older should have a mammogram every 1 to 2 years. Transgender women who have taken gender-affirming hormones for more than five years and are between the ages of 40 and 74 should consider getting a mammogram every 2 years.

What else can I do to prevent and detect breast cancer?

Adopt healthier lifestyle habits, like eating a healthy diet, exercising regularly, not drinking too much alcohol, and not smoking.

Talk to your healthcare provider about your personal and family risk factors for breast cancer so they can give you advice.

Self-examine your breasts regularly. Let your healthcare provider know if you notice any changes, including:

  • Breast lumps
  • Changes in your breast size or shape
  • Changes in how your breast or nipple skin look or feel
  • Your breasts or nipples feel tender
  • Your nipples are leaking fluid