Learn More About Breast Cancer

1 in 8 women in the US will develop breast cancer in their lifetime.

Over 268,600 cases of breast cancer will be diagnosed this year in US women, and over 2,500 in US men. Breast cancer will claim approximately 41,000 American lives this year alone.

As diagnosis and treatments for breast cancer improve, more and more women are surviving their diagnosis – and surviving longer. Approximately 90 percent of those diagnosed with breast cancer now survive five years after diagnosis.

The findings of AICR's latest report on breast cancer continue to support our recommendation: eating a plant-based diet, maintaining a healthy weight, and getting regular physical activity remain the best strategies for reducing breast cancer risk.

Premenopausal Breast
Postmenopausal Breast


Drinking alcohol – in any form – raises breast cancer risk.

  • Alcohol influences blood levels of estrogen and other hormones in ways that may make cancer more likely.
  • Alcohol is a recognized carcinogen. It can cause cellular damage that can trigger cancer development.

Carrying excess body fat increases risk for post-menopausal breast cancer.
Of all the potential lifestyle links studied, the evidence that being at a healthy weight improves breast cancer survivorship is the most consistent. There are several potential ways that excess fat cells may lead to worse outcomes:

  • Fat tissue causes inflammation, which can promote cancerous changes in healthy cells. 
  • Being overweight and obese increases blood levels of insulin and related hormones that can encourage the growth of cancer.

*Current evidence suggests that carrying excess body fat may offer some protection against pre-menopausal breast cancer; however, evidence is convincing that body fat is a cause of the much more common post-menopausal form of breast cancer.

Physical activity
Being active decreases risk for post-menopausal breast cancer. Vigorous activity decreases risk for pre-menopausal breast cancer. Regular physical activity helps regulate hormone levels.

Some evidence indicates that people who are physically active (both before and after diagnosis) have a greater chance of surviving breast cancer. There are several possible reasons for this, and more research is needed to investigate this link.

Breastfeeding: If you give birth, breastfeeding your baby lowers your risk of both pre- and post-menopausal breast cancers.

  • Breast cells undergo physical and horomonal changes during pregnancy and breastfeeding that offer protection against cancer.
  • The shedding of tissue during lactation and the elimination of breast cells at the end of lactation both provide protection.

Eating Healthy: Compared to the evidence on body weight and physical activity, there are relatively few studies on diet’s role in breast cancer survival. But the report found intriguing evidence for:

  • Fiber - In some studies, people who eat more foods containing fiber (both before and after diagnosis) have a lower risk of dying from breast cancer.
  • Soy - Some evidence suggests that breast cancer survivors who eat more foods containing soy have a lower risk of dying from the disease.
  • Dietary Fat - There are indications that people who consume a diet high in fat and saturated fat before developing the disease may have an increased risk of dying following a diagnosis of breast cancer.

Family History: Inheriting BRCA-1 or other “cancer genes” does increase risk, but these inherted genetic factors are responsible for only about 5 to 10 percent of all breast cancers.