While the cause of breast cancer is still unknown, research has revealed a number of factors that may affect your risk of it. Some influence risk more than others, and your risk can change over time. Having any of them does not mean you will get this disease, nor does their absence mean you won’t. Many of these factors are related to the risk associated with uninterrupted exposure over a prolonged time to estrogen, the female hormone that stimulates breast cell growth. Some of the lifestyle-related factors you may be able to control, but other factors are beyond your control, such as your age. The number one risk is being female, and as a woman ages, her risk increases. Women of any age, however, may develop breast cancer, so all women should know their own risk factors. This will enable you to manage the ones you can and to be sure you are doing the screening methods appropriate for your level of risk (ask your medical professional about these).


Being overweight after menopause raises risk because fat tissue is the body’s chief source of estrogen after the ovaries stop producing it.

Although we don’t know for certain what foods increase or decrease risk, a low-fat diet high in fruits and vegetables is recommended.

Alcohol consumption
Risk increases with the amount of alcohol a woman drinks. Alcohol can restrict the liver’s ability to control blood levels of estrogen.

Evidence is growing that frequent and regular exercise can reduce risk.

Current or recent oral contraceptive use
Using birth control pills may slightly raise a woman’s risk. This risk returns to normal over time once off the pills.

Hormone therapy after menopause
The risk of using hormone therapy after menopause varies by type, duration, and elapsed time since use. The American Cancer Society suggests you carefully weigh the risks and benefits with your doctor before choosing to use any hormone therapy, including “bio-identical” hormones, after menopause.


Family history of breast cancer
Having one first-degree relative (mother, daughter, sister) with breast cancer increases your risk; having more than one increases it even more. Women with a family history of breast or prostate cancer in an immediate male relative may also have an increased risk. Generally, the younger the age at diagnosis of any of these close relatives, the greater the risk. If a close family member has an identified gene mutation, such as BRCA1 or BRCA2, we suggest you discuss your risk with a medical professional trained in risk assessment.

Personal history of cancer
Having a diagnosis of invasive breast cancer, ductal carcinoma in situ (DCIS), Hodgkin’s disease, or other cancers increases your risk. Having a diagnosis of lobular carcinoma in situ (LCIS) creates a strong increase in risk.

High breast density
Women with dense breast tissue (seen on a mammogram) have a higher risk.

Radiation therapy to the chest
Having radiation to the chest area as a child or young adult as treatment for another cancer (such as Hodgkin’s disease or non-Hodgkin’s lymphoma) significantly increases risk.

Menstrual periods and menopause
Women who have had more menstrual cycles because they had their first period before 12 or did not go through menopause until after 55 have a slightly higher risk because of more prolonged exposure to estrogen.

Pregnancy and breastfeeding
Women who have never had children or had their first child after 35 have a slightly higher risk. Conversely, pregnancy and breastfeeding reduce the overall number of menstrual cycles in a women’s lifetime, which may reduce risk.

Certain benign breast conditions
Certain non-cancerous breast conditions, such as atypical hyperplasia, can raise a woman’s risk.

NOTE: The varying risk levels of the listed factors are covered more fully on the Susan G. Komen for the Cure® website (www.komen.org). Other established risk factors listed there include Ashkenazi Jewish heritage, being tall, high socioeconomic status, and mammography. Probable risk factors, recognized as linked though not as solidly as the established ones, include high bone density and light at night/shift work.

Because it would be impossible to remove all potential risks for breast cancer from your life, the best way for you to take charge of your breast health is to live a healthy lifestyle and practice early detection, which involves discussing your individual risk factors and appropriate screening methods and schedule with your doctor.

Alicia and her mom say, “Know your risk factors.”


Debbie reminds us, “Only 15% of all breast cancers involve a family history, so know all your risk factors.”