Breast cancer continues to be the leading cause of death among middle-aged women. Over the past year, more than 194,000 new cases of breast cancer were recorded in the United States, of which approximately 20% did not access timely treatment despite the availability of educational resources. Breast cancer is a malignant tumor that develops in the breast cells of a woman or man. Although this condition is not gender specific, it is more prevalent in middle-aged to older women. Its malignant foundation causes it to also take over surrounding tissues if left untreated. The proximity of the breasts to the heart and lungs is the predominant cause of deaths associated with breast cancer. It is unofficially hereditary, because your risk of developing cancer is doubled by the extent of the genetic mutation in your family. Most breast lumps are benign, but it is in your best interest to have a biopsy to prove otherwise. The female breast is made up primarily of milk-producing glands called lobules, small tubes that carry milk to the nipple from lobules called ducts, and stroma, the fatty connective tissue surrounding the ducts, lobules and blood vessels and lymphatics. A large majority of breast cancers begin in the cells that line the ducts and lobules, while a small percentage begin in other tissues. The exact cause of breast cancer remains unknown, but scientists have identified a number of risk factors that increase the chances of developing breast cancer. contract the tumor. Factors such as age are beyond the person's control, while risks such as drinking habits can be changed as a preventative measure. The risk of developing breast cancer increases with age, with approximately 80% of breast cancer cases developing in women aged 50 and over. However, breast...... middle of paper...... Antoniou A, Pharoah PD, Narod S, et al. Average risks of breast and ovarian cancer associated with BRCA1 or BRCA2 mutations detected in case series not selected for family history: a combined analysis of 22 studies. American Journal of Human Genetics 2003; 72(5):1117-1130.Walsh T, Casadei S, Coats KH et al. Spectrum of mutations of BRCA1, BRCA2, CHEK2 and TP53 in families at high risk of breast cancer. JAMA 2006; 295(12):1379-1388. “BRCA1 and BRCA2: cancer risk and genetic testing. » BRCA1 and BRCA2: cancer risk and genetic testing. National Cancer Institute, January 22, 2014. Web. May 16, 2014. “Breast Cancer.” Breast cancer. Genetics Home Reference, August 2007. Web. May 16, 2014. Slowik, Guy. “What are the causes of breast cancer?” EhealthMD. EhealthMD, March 20, 2012. Web. May 18, 2014. “What is breast cancer?” » Breast cancer. American Cancer Society, January 31, 2014. Web. May 16 2014