Breast Cancer Advice. Keep up to date with the latest information and treatment of breast cancer.
A Member of the Healthscout Network

What are the causes and risk factors of breast cancer?

The exact causes of breast cancer remain uncertain. Changes or mutations (inherited or spontaneous) allow breast cancer to develop. BRAC1 and BRAC2, two genes linked to breast cancer, are mutated in 5 to 10% of cases.

Risk factors for developing breast cancer:
  • Gender and Age: Women are 100 times more likely to develop breast cancer than men, and the risk increases with age.
  • Genetics: A heightened risk for developing breast cancer can be inherited (passed through genes) - having an immediate relative (mother, sister, or daughter) with the disease doubles the chance of getting breast cancer. Chest irradiation, which can cause genetic mutations, increases the risk.
  • Estrogen: Elevated estrogen exposure occurring from early onset of menstrual periods (prior to age 12) or late menopause (after age 55) increases the chance of developing breast cancer. First full term pregnancy after the age of 30 as well as never becoming pregnant also increase the risk of developing breast cancer. Alternatively, breast-feeding for longer than one year, first menses after age 15, and premenopausal obesity are all associated with lower estrogen levels and a reduced risk of developing breast cancer.
  • Breast Abnormalities: The development of benign breast disease increases the risk for development of breast cancer slightly.
  • Hormone Replacement Therapy (HRT): The Women's Health Initiative clinical trial showed a 26% increase in breast cancer in women who took combined estrogen and progestin (trade name Prempro) [Women's Health Initiative HRT Study]. Another large clinical study conducted in England found an increased risk of developing breast cancer following estrogen only HRT treatment (trade name Premarin) [Million Women Study]. Five years after discontinuation of HRT, the risk for developing breast cancer returns to the background level.
  • Alcohol: Drinking one alcoholic beverage a day is associated with a slight risk for breast cancer, while drinking two to five alcoholic beverages per day increases the risk by 1.5-fold.
< previous home next >

Disclaimer: The information provided on this website is for educational purposes only and does not serve as a replacement for care provided by your own personal health care team. This website does not render or provide medical advice, and no individual should make any medical decisions or change their health behavior based on information provided here. All pertinent content provided on this website should be discussed with your personal physician to evaluate whether it has any relevance to or impact on your specific condition. Reliance on any information provided by this website is solely at your own risk.

Jul 25, 2008
Powered By HealthLine
New! For timely and trustworth health information, expert advice and much more, visit Breast Cancer Connection
Patient Guide
Health Videos
Health Encyclopedia
Health News Archive
Affiliate Information
HealthScout Network
Contact Us
Privacy Policy
Terms of Use

We comply with the HONcode standard for trustworthy health
verify here.
About The HealthScout Network Contact Us
Copyright 2001. The HealthCentralNetwork, Inc. All rights reserved.
Privacy Policy  Terms of Service  

To find more information on specific conditions, please visit our partner sites: