Breast Cancer: Causes and Risk Factors You Should Know

What Causes Breast Cancer?

Breast cancer begins when abnormal cells grow uncontrollably and form a lump or mass in the breast. These cancer cells may spread to nearby lymph nodes or other parts of the body. Most cases start in the milk ducts or lobules but can also develop in other breast tissue.

While the exact cause of breast cancer is not fully known, researchers have identified a combination of genetic, hormonal, lifestyle, and environmental factors that may increase your risk.

Top Risk Factors for Breast Cancer

Having one or more risk factors doesn't mean you’ll get breast cancer—but being informed can help with prevention and early detection.

1. Biological and Genetic Risk Factors

• Gender: Women account for nearly 99% of all breast cancer cases, but men can also be affected.
• Age: Risk increases significantly after age 50.
• Genetic Mutations: Inherited mutations in the BRCA1 or BRCA2 genes raise the lifetime risk. Learn more about signs of a cancerous lump.
• Family History: Having a first-degree relative with breast or ovarian cancer increases your risk.
• Personal History: A previous diagnosis of breast cancer or certain benign conditions like atypical hyperplasia raises your chances of recurrence.
• Radiation Exposure: Chest radiation therapy, especially in childhood or early adulthood, is linked to higher risk later in life.

2. Hormonal and Reproductive Risk Factors

• Early Menstruation (Before Age 12): Longer lifetime exposure to estrogen may elevate risk.
• Late Menopause (After Age 55): Prolonged hormone exposure is a contributing factor.
• Pregnancy History: Never being pregnant or having your first child after age 30 may increase your risk.
• Hormone Replacement Therapy (HRT): Combined estrogen and progesterone therapy, especially for more than five years, raises the risk of developing breast cancer.

3. Lifestyle and Environmental Risk Factors

• Obesity: Particularly after menopause, excess body fat increases estrogen levels.
• Alcohol Consumption: Even moderate alcohol intake (more than one drink per day) raises breast cancer risk.
• Lack of Physical Activity: Sedentary habits contribute to higher hormone levels and inflammation.
• Poor Diet: Diets high in processed foods, red meats, and low in fiber may increase risk.

Looking for ways to reduce risk? Read 5 Signs of Good Breast Health.

How to Lower Your Breast Cancer Risk

While you can’t change certain factors like your age or genetics, lifestyle changes can make a big difference:

• Maintain a healthy weight
• Exercise regularly
• Limit alcohol intake
• Eat a diet rich in fruits, vegetables, and lean protein
• Get regular screenings and checkups
• Know your family history and ask about genetic counseling if needed

Learn how early detection improves survival rates.

When to Get Screened

Early detection is key to better outcomes. We recommend the following:

• Mammograms: Start annual screenings at age 40—or earlier if you have a family history.
• Self-Exams: Perform monthly self-checks to notice any changes.
• Clinical Breast Exams: Schedule regular checkups with your provider.

Need imaging? Visit our Imaging Center for 2D and 3D mammography.

Get Specialized Breast Care at BASS Cancer Center

At BASS Cancer Center, we provide expert care for breast cancer diagnosis, treatment, and recovery. Our dedicated team of breast surgeons works with you to create a personalized care plan focused on your health and peace of mind.

Book an appointment with a BASS Medical Group specialist today.