Breast Cancer Risks

There are a variety of factors that can cause someone to be at increased risk for breast cancer. Risks can be divided into factors we can change and others we cannot. Lifetime exposure to estrogen also plays a role in breast cancer risk. By familiarizing yourself with breast cancer risk, you are better able to understand lifestyle changes that can improve your chances of avoiding a breast cancer diagnosis.

The risks for breast cancer that are considered unchangeable, i.e. non-modifiable, include gender, race, age and genetics. Although not thought of as much, men can get breast cancer. Yet, breast cancer is 100 times more common in woman. Therefore, being a woman can increase someone’s risk for breast cancer. Secondly, Caucasian woman, followed by African Americans, are at the highest risk of breast cancer. Additionally, breast cancer risk increases with age. Women in their 60s and 70s are at the highest risk. Tall stature and increased breast density, or firmness, has also been associated with increased risk of breast cancer. Finally, certain genetic syndromes increase one’s risk of breast cancer, such as the BRCA gene mutation. The BRCA 1 and 2 gene mutations are the most common inherited breast cancer syndromes, representing 5-10% of all breast cancers. Exposure to radiation, such as in the cases of treatment for Hodgkin’s lymphoma, can significantly increase breast cancer risk. Use of estrogen or progesterone pills after menopause can increase the risk of breast as well, although the risk occurs after 3 years of use.

Some risk factors center on a woman’s lifetime exposure to estrogen. Increased levels of estrogen increase the risk of breast cancer. Body fat should be thought of as an organ. Our body fat serves many purposes. One of the functions of our body fat is to produce estrogen. This is way it is thought that increased weight is a risk factor for breast cancer. This increased risk of breast cancer with an BMI greater than 30 only applies to women after menopause. Also, when a woman is pregnant, estrogen is suppressed for the duration of the pregnancy. This is why it is thought that women without children are at increased risk compared to women with children. Additionally, beginning a menstrual cycle at an early age increases lifetime exposure to estrogen, which also increases the risk of breast cancer. Having menopause later in life also increases a woman’s lifetime exposure to estrogen and serves as a risk factor as well. A family history of breast or ovarian cancer also increases risk of having this disease. Therefore, it is important to know you family history is essential.

Other risk factors center on things we can control. Regular exercise can decrease breast cancer by 25%. Adequate vitamin D in women after menopause and breastfeeding are also protective against breast cancer. On the other hand, alcohol intake and tobacco use can increase breast cancer risk. Night shift work is recognized as a probable carcinogen, yet studies are mixed on its effects.

There are many risk factors for breast cancer. Some risks we can control and others we cannot. Even in a woman with an absence of major risk factors, breast cancer awareness and a diligence for screening remains important. In all, weight loss, regular exercise, adequate vitamin D, tobacco cessation and decreased alcohol use can go a long was in decreasing breast cancer risk.

REFERENCES
1. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2018. CA Cancer J Clin. 2018 Jan;68(1):7-30. doi: 10.3322/caac.21442. Epub 2018 Jan 4. PMID: 29313949.