Breast cancer is currently the most frequently diagnosed malignancy in women in the United States and is the second leading cause of cancer-related mortality.1 In 2021, there will be approximately 330,840 new cases of breast cancer (281,550 cases of invasive breast cancer and 49,840 cases of ductal carcinoma in situ) diagnosed in women in the United States, and approximately 43,600 women will die from the disease.2 The incidence rates of breast cancer have increased in recent years by 0.5% annually. However, the rates of breast cancer deaths have been steadily declining.2 This is the combined result of better education, widespread screening programs, and more effective treatments. There are currently more than 3.8 million breast cancer survivors in the United States. This number reflects women being treated for the disease, as well as those who have completed treatment.1 How much do you know about breast cancer?
Approximately 1 in 8 women in the United States will develop invasive breast cancer during their lifetime.1 There are many types of breast cancer, determined by the specific cells in the breast that are affected.2 The majority of breast cancers are carcinomas (tumors that originate in the epithelial cells that line organs and tissues in the body). Most carcinomas that develop in the breast are known as adenocarcinomas. These cancers start in the cells of milk ducts or milk-producing glands. A very small percentage of breast cancers, such as Paget disease of the breast and sarcomas, originate in other types of cells in the breast. Although survival rates for patients with breast cancer vary based on several factors, the overall 5-year relative survival rate is 99% for localized disease, 85% for regional disease, and 28% for distant-stage disease, emphasizing the importance of early detection and treatment.2