Breast cancer, the most frequently occurring cancer in women, is a major public health problem, with 1,384,155 estimated new cases worldwide with nearly 459,000 related deaths. Breast cancer is highly heterogeneous in its pathological characteristics, some cases showing slow growth with excellent prognosis, while others being aggressive tumors. Current predictions and statistics suggest that both worldwide incidence of breast cancer and related mortality are on the rise. According to 2012 GLOBOCAN statistics, nearly 1.7 million women were diagnosed with breast cancer with 522,000 related deaths-an increase in breast cancer incidence and related mortality by nearly 18 % from 2008. According to American Cancer Society, one in eight women in the United States will develop breast cancer in her lifetime. It has been predicted that the worldwide incidence of female breast cancer will reach approximately 3.2 million new cases per year by 2050. These numbers reflect the magnitude of breast cancer incidence, its effect on society worldwide and the need for urgency for preventive and treatment measures. While technological advances in medical sciences and health care have made it possible to detect the disease early and to start the treatment early on to prevent the progress of the disease into a metastatic state, there are several unanswered questions with regard to the molecular mechanisms that underlie the aggressiveness of certain forms of this disease. Epidemiological studies suggest that addressing socio economical issues is utmost important, so that all women have equal access to medical care from screening to advanced treatment, and only such decisive action can help reduce the worldwide burden of breast cancer.
Keywords: Breast cancer; Epidemiology; Etiology.