Considerations on the prevention of female breast cancer

Abstract

Breast cancer control should place emphasis on preventing cancers or detecting cases in early stages. Prevention not only focuses on the risks associated with breast cancer but also on protective factors. Some factors that increase breast cancer risk, such as postmenopausal obesity, high-dose exposure to ionizing radiation, exposure to pesticides/organochlorines and tobacco use, are modifiable; other risk factors, such as female gender, age, early menarche, late menopause, late first full-term pregnancy, previous breast and ovarian cancer, benign breast disease, high breast density, genetic mutations (BRCA1 and BRCA2), or family history of breast cancer, cannot be modified. Most of these risk factors are associated with only a moderate increase in risk (two- or three fold), suggesting that multiple factors may play a role in each woman's disease and that unrecognized factors may exist. On the other hand, there are two principal components for early detection: education to promote early diagnosis, and screening. The evidence available to date, from population-based controlled trials examining the effectiveness of routine screening with mammography suggests a 25% reduction in breast cancer mortality. In addition, there is only indirect evidence that screening by clinical breast examination will reduce the number of breast cancer deaths.