Screening for breast cancer

Abstract

Breast cancer is a multifactorial disease that has a worldwide annual incidence of over 1 million cases. In the UK this equates to over 39000 new diagnoses per year. Most of these cases occur in postmenopausal women, and the incidence in both this age group and in younger women is rising. Most of the major risk factors for breast cancer such as female sex, age and a family history of the disease cannot be avoided. However, there is established evidence that earlier detection of breast cancer through mammographic screening does significantly reduce mortality, by up to 24%. Since its inception in 1989, the National Health Service Breast Screening Programme (NHSBSP) has become increasingly effective at detecting breast cancer in the target population of women aged over 50, and together with advances in surgery, chemotherapy and other adjuvant medical treatments, mortality from breast cancer is significantly decreasing. This contribution aims to explore the principles behind the NHSBSP, and will review the key evidence which supports it. The advantages and pitfalls of screening will be examined and an overview of the actual screening and assessment process is included. Screening in high-risk groups is a new and controversial area that is now gaining prominence, and new imaging techniques being used in such groups, in addition to the screening and assessment of breast cancers in the conventional age range, will be covered.