Risk Factors and Prevention

Understanding Risk and Prevention 

Summary Tables of Risk Factors 

• Introduction  
• Understanding risk   
• Breast Cancer Risk Assessment Tool (Gail model)  
• Understanding prevention  

• Breast cancer risk factors table 
• Risk factors summary table of relative risks 

Topics for People at Higher Risk of Breast Cancer 

Other Issues Related to Breast Cancer Risk 

• Gene mutations and genetic testing 
• Options for women at higher risk    
• More frequent or earlier screening 
• Preventive surgery 
• Risk-lowering drugs (tamoxifen and raloxifene)  
• Clinical trials for women at higher risk 

• Healthy behaviors 
• Race and ethnicity 
• Breast cancer risk among lesbians and women who partner with women 
• Breast cancer and the environment 
• Emerging areas in estimating risk and risk reduction 
• Questions for your provider 
• Glossary 
• References 

Factors that Affect Breast Cancer Risk
(listed according to level of evidence and strength of association)  

Factors that Do Not Increase Breast Cancer Risk 
(listed alphabetically)

• Age 
• Being female 
• Inherited genetic mutations 
• Family history of breast, ovarian or prostate cancer 
• Breast density on mammogram 
• Benign breast conditions (benign breast disease, hyperplasia) 
• Lobular carcinoma in situ (LCIS) 
• Personal history of cancer (including invasive breast cancer, DCIS, Hodgkin's disease and other cancers) 
• Radiation treatment (radiation exposure) 
• Childbearing (age at first birth and number of children) 
• Blood estrogen levels  
• Age at first period 
• Age at menopause 
• Drinking alcohol 
• Ashkenazi Jewish heritage 
• Body weight and weight gain 
• Birth control pill use 
• Height 
• Socioeconomic status 
• Postmenopausal hormone use 
• Breastfeeding 
• Blood androgen levels 
• Bone density 
• Light at night and shift work 
• Exercise (physical activity) 
• Breast cancer risk factors table 

• Factors that do not increase breast cancer risk 
• Abortion  
• Blood organochlorine levels (exposure to certain types of pesticides and industrial chemicals)  
• Breast implants  
• Electromagnetic fields (EMF)  
• Hair dyes  
• Breast cancer risk factors table 
   

Factors Under Study  
(listed alphabetically)

Factors Not Likely Related to Breast Cancer Risk 
(listed alphabetically)

• Factors under study 
• Antibiotic use  
• Aspirin use  
• Body care cosmetics containing parabens  
• Breast size  
• Caffeine  
• Cell phone use  
• Dairy products 
• Dietary fat  
• Folic acid (folate) and multivitamin use 
• French fry consumption  
• Fruits, vegetables and carotenoids  
• Glycemic index and insulin  
• Hair relaxers  
• In utero exposure to DES and breast cancer risk among offspring  
• Left-handedness  
• Meat consumption  
• Migraine headaches  
• Protein hormones (prolactin and IGF-1) 
• Secondhand smoke  
• Smoking  
• Soy and phytoestrogens  
• Stress  
• Vitamin D  
• Breast cancer risk factors table  

• Factors not likely related to risk  
• Bras/underwire bras  
• Breast milk (having been breastfed as an infant) 
• Deodorant/antiperspirant use  
• Fertility drugs 
• Plastics  
• Trauma to the breast  
• Breast cancer risk factors table  

Risk Factors Research Tables 

Risk-Lowering Drugs (Chemoprevention) Research Tables 

• Table 1: Body weight and breast cancer risk  
• Table 2: Weight gain and breast cancer risk 
• Table 3: Alcohol and breast cancer risk 
• Table 4: Physical activity and breast cancer risk  
• Table 5: Breastfeeding and breast cancer risk  
• Table 6: Blood estrogen levels and breast cancer risk  
• Table 7: Blood androgen levels and breast cancer risk  
• Table 8: Postmenopausal hormone use and breast cancer risk  
• Table 9: Birth control pills and breast cancer risk  
• Table 10: Age at menopause and breast cancer risk  
• Table 11: BRCA1 and BRCA2 gene mutations and cancer risk  
• Table 12: Hyperplasia and breast cancer risk  
• Table 13: Light at night/shift work and breast cancer risk  
• Table 14: Dairy products and breast cancer risk 
• Table 15: Dietary fat and breast cancer risk  
• Table 16: Fruits and vegetables and breast cancer risk  
• Table 17: Carotenoids and breast cancer risk  
• Table 18: Meat and breast cancer risk 
• Table 19: Soy and breast cancer risk  
• Table 20: Vitamin D and breast cancer risk 
• Table 21: IGF-1 and breast cancer risk  
• Table 22: Smoking and breast cancer risk  
• Table 23: Secondhand smoke and breast cancer risk  
• Table 24: Hair dyes and breast cancer risk 
• Table 25: Abortion and breast cancer risk 
• Table 26: Electromagnetic fields and breast cancer risk  
• Table 27: Blood organochlorine levels and breast cancer risk  
• Table 28: Breast implants and breast cancer risk 

• Table 29: Chemoprevention—the use of tamoxifen and raloxifene to reduce the risk of breast cancer 

To learn more about the role of the environment in breast cancer, Komen sponsored a new study from the Institute of Medicine, "Breast Cancer and the Environment, a Life Course Approach". Read the final report.