Breast cancer as a global epidemic

摘要

Breast cancer is the most common cancer that affects women worldwide with an estimated 1.3 million new cases diagnosed annually. The highest incidence remains in the developed world; however, incidence rates are steadily rising in other areas of the world. Between 2002 and 2020, breast cancer incidence and mortality are expected to rise 50%, with the greatest rise occurring in developing countries. Several theories have been proposed to explain this rise in incidence, and most turn to the lifestyle changes that occur as countries become more westernized. For example, in India the most common cancer type among women is cervical; however, once these women migrate to the USA, breast cancer becomes the most common cancer. Other studies evaluating breast cancer incidence in immigrants from low-resource or transitioning countries have shown similar changes. Urbanization within countries demonstrates parallel increases; for example, there has been a 20-30% increase in breast cancer over the past decade in China's urban registries. This shift relates to better screening mechanisms, as well as diet and lifestyle changes.