Breast Cancer Risk Factors

Your risk for breast cancer depends on many factors, including your age, health history, genetics and lifestyle. Understanding your breast cancer risk plays an important role in detecting breast cancer early and taking steps toward prevention.

At Penn Medicine Lancaster General Health, we provide comprehensive risk assessment, screening, genetic counseling and support for anyone who may be at an increased risk for breast cancer. When we identify your risk, we can deliver the personalized and preventive care you need.

Estimate your five-year and lifetime risk of breast cancer.

Understanding Breast Cancer Risk

Approximately one out of every eight women will develop breast cancer, and the risk for men is less. But there are certain factors that increase your risk for breast cancer. Some of those factors are with you from birth and cannot be changed. Others are lifestyle choices. Eliminating those risk factors may help you prevent breast cancer.

Fixed Risk Factors for Breast Cancer

Some factors that put you at a higher risk for breast cancer are out of your control, including:

• Gender. Women are much more likely to develop breast cancer than men.
• Age. Breast cancer risk increases with age, with most breast cancers developing after the age of 50.
• Genetic mutations. Approximately 5 to 10 percent of diagnosed breast cancers are associated with inherited gene mutations (changes). BRCA1 and BRCA2 gene mutations are the most common mutations related to breast cancer, though others can also increase your risk.
• Family history. Your risk increases if your mother, sister, father or child had breast cancer, especially if the diagnosis was before the age of 50. Use this form to collect your family’s medical history.
• Menstrual and reproductive health history. A woman’s risk of breast cancer increases if she menstruates early (before the age of 12), enters menopause later (after 55), gives birth at an older age or never gives birth.
• Dense breast tissue. Having dense breasts increases your risk and may make breast cancer harder to detect.
• Personal breast history. Some benign breast conditions or a previous breast cancer increase the chances of developing a new breast cancer.

Risk Factors You Can Change to Prevent Breast Cancer

Changing your lifestyle may help with breast cancer prevention. Reversible factors that increase your risk for breast cancer include:

• Physical inactivity: A sedentary lifestyle makes you more likely to develop breast cancer.
• Being overweight or obese: An unhealthy weight increases your risk of breast and other cancers, especially if you are overweight or obese following menopause.
• Alcohol consumption: Frequently drinking alcohol increases your risk of breast and other cancers.
• Taking hormones: Your risk of breast cancer increases if you take hormone replacement therapy for more than five years during menopause. Some oral contraceptives (birth control pills) also raise your risk.
• Giving birth: Your chances of breast cancer increase if you never have biological children, have your first child after the age of 35 or never breastfeed.
• Radiation to the chest: Having radiation therapy to the chest before the age of 30 may increase your risk.