• Breast Cancer Awareness Month

    By Jayasri Ghosedastidar, PhD
    Full-time Adjunct Professor, School of Health Sciences

    October is Breast Cancer Awareness Month, a time when we can come together and work as individuals, communities, and organizations working towards fighting and preventing this disease. Let’s not forget that in the United States, the chance that a woman will have invasive breast cancer sometime during her life is about 1 in 8, and breast cancer is the second leading cause of cancer death in women. Let’s spread the message of hope—millions of women are surviving breast cancer. Know your risk factors and get screened by routine mammograms to help detect the disease earlier.

    What are the causes of breast cancer? Who is at risk? 

    I am lucky to say that I have no family history of breast cancer within my close relatives, but I have a childhood experience with this disease. One of my sister’s friends lost her mother to breast cancer and that was the first time I witnessed the trauma, sadness, and devastation it caused. At Kaplan University, I teach a course in diseases and every term my students and I become emotional as soon as we hit this topic. So, I decided to learn more about breast cancer. In this article, I’d like to focus on the causes and the risk factors that can increase one’s chance of developing breast cancer.

    Like many other cancers, the cause of breast cancer is not yet fully understood. Breast cancer occurs due to uncontrolled growth of breast cells, and the majority of this cancer starts in breast tissue that are made up of glands for milk production, called lobules and ducts, that carry milk to nipples. When normal epithelial cells in milk ducts are replaced with cancer cells, it is called ductal carcinoma in situ, which is a non-invasive form of breast cancer. 

    Lobular carcinoma in situ (LCIS) occurs when cancer cells grow in the lobules and is considered as a marker for increased risk of developing invasive cancer. With aging, breast cancer risk as well as death rate increases. Risk factors that are not modifiable include age, family history, early menarche, and late menopause. But there are some risk factors that can be modified which include obesity, use of combined estrogen and progestin menopausal hormones, alcohol consumption, and breastfeeding (Breast Cancer Facts & Figures 2015-2016).

    Family History

    Studies show that women with a family history of breast cancer in first degree relatives (mother, sister or daughter, father, brother or son), have twice the risk of developing breast cancer compared to women without such family history (Breast Cancer Facts & Figures 2015-2016).


    Mutations in the BRCA1 and BRCA 2 genes, which are tumor suppressor genes, are most common inherited factors and significantly increases the risk of breast cancer. Upon examining relevant epidemiological and biological evidences, Wiseman (2000) reports that genetic inheritance is not the main cause of breast cancer–cancer predisposition genes are associated with only 4% to 8% of breast cancer cases. In most cases of breast cancers, genetic changes or mutations are acquired during a person’s lifetime, called somatic mutations and these changes are not inherited (Genetics Home Reference, 2016).


    Breast cells normally grow and divide in response to hormone estrogen, progesterone, and prolactin. Obesity in postmenopausal women increases the level of estrogen and thus increase the risk of breast cancer. In women, ovaries are the main source of the hormone estrogen until menopause, after which only the body fat tissue produces the hormone in small amounts. About 2 in 3 breast cancers are hormone-receptors positive which means they contain the receptors for hormone estrogen and/or progesterone. Estrogen helps proliferation of these cancer cells.

    The objective of hormone therapy is to lower estrogen level or stop its action. Tamoxifen is one such drug that blocks estrogen receptors in breast cancer cells. Aromatase inhibitor is another drug that inhibits the enzyme aromatase in fat tissue, which is involved in making small amount of estrogen in post-menopausal women (American Cancer Society, 2016).

    High Breast Density

    Studies show that breast tissue density (amount of breast’s glandular and connective tissue compared to fatty tissue) has been linked to higher risk of breast cancer. Breast density is influenced by many factors that include genetics, age, pregnancy and menopause (Breast Cancer Facts & Figures 2015-2016).

    Reproductive Life

    Finally, some studies show that women with no children or women who have children at an older age (at or after 35 years) may be at higher risk for breast cancer. Other studies show that use of certain hormones (in birth control pills) slightly increases the breast cancer risk. However,  the risk may decrease as one stops using the hormones (Breast Cancer Facts & Figures 2015-2016).

    Learn About Ways to Stay Healthy 

    According to the American Cancer Society, millions of women in the United States are surviving breast cancer through improvements in treatment and early detection. This Breast Cancer Awareness Month, take the time to learn more about the risk factors and talk to your physician about when to start and how often to get a mammogram. 

    For additional resources and information, visit some of the references used in this article: 

    Breast Cancer Facts and Figures 2015-2016. “PDF file”. Retrieved from http://www.cancer.org/acs/groups/content/@research/documents/document/acspc-046381.pdf

    Cancer Treatment Centers of America. (2015). Breast Cancer Risk Factors. Retrieved from http://www.cancercenter.com/breast-cancer/risk-factors/

    American Cancer Society. (2016, February 22). Hormone therapy for breast cancer. Retrieved from http://www.cancer.org/cancer/breastcancer/detailedguide/breast-cancer-treating-hormone-therapy

    American Cancer Society. (2016, February 22). Do we know what causes breast cancer? Retrieved from http://www.cancer.org/cancer/breastcancer/detailedguide/breast-cancer-what-causes

    Wiseman, R.A. (2000). Breast cancer hypothesis: a single cause for majority of cases. J Epidemiol Community Health. 54, 851–858. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1731579/pdf/v054p00851.pdf

    Genetics Home Reference. (2016, March 21). Breast Cancer. Retrieved from https://ghr.nlm.nih.gov/condition/breast-cancer


    Jayasri Ghosedastidar, PhD, is an adjunct faculty member at Kaplan University. The views expressed in this article are solely those of the author and do not represent the view of Kaplan University. 

    The contents of this article are presented for informational purposes only, and are not to be relied upon for medical purposes. Always check with a health care professional regarding any questions you may have regarding medical issues.



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