The Etiology of Breast Cancer

The etiology of breast cancer is attributed to a complex interaction between various modifiable and non-modifiable factors. This etiology is determined by genetics, environmental, nutritional, hormonal, and heritable elements that contribute to the development of this disease. Risk factors include prior history of breast cancer, positive family history, obesity, tall stature, smoking, alcohol consumption, early menarche, late menopause, sedentary lifestyle, nulliparity and hormone replacement therapy. Factors associated with decreased risk of breast cancer include multiparity, history of breastfeeding, physical activity, weight loss, and prophylactic surgical and medical interventions. In the United States, approximately one in eight women will be diagnosed with breast cancer in her lifetime. This disease is more common in white, post-menopausal females. Risk increases with older age with about 80% of breast cancer patients being older than 50 years. Analyzing the etiology of breast cancer allows for the development of improved screening and treatment interventions. In this chapter, the etiology of breast cancer along with the risk factors associated with this disease are discussed.