Every year, breast cancer kills more than 500,000 women around the world. In resource-poor settings, a majority of women with breast cancer are diagnosed at an advanced stage of disease; their five-year survival rates are low, ranging from 10-40%. In settings where early detection and basic treatment are available and accessible, the five-year survival rate for early localized breast cancer exceeds 80%.

Breast cancer can be detected early through two strategies:

early diagnosis and screening. Early diagnosis is based on improved public and professional awareness of signs and symptoms associated with cancer; it entails recognizing possible warning signs of cancer and taking prompt action. Screening involves the systematic use of testing, such as mammography, across an asymptomatic population to detect and treat cancer or pre-cancers. The new WHO position paper examines the balance of benefits and harms in offering mammography screening to women after the age of 40 in a variety of settings.