Breast cancer screening

In our society, there is a deeply rooted belief that the early detection of cancer is invariably beneficial, and evidence to the contrary is often viewed with skepticism. Today, several breast cancer screening methods are available, and it is important that we evaluate these critically and base screening recommendations on good evidence rather than assumptions. To realize how assumptions about cancer screening can be misleading, consider the history of lung cancer screening. For many years, it was assumed that screening for lung cancer with sputum cytology or chest radiographs would be beneficial. Eventually, four randomized prospective trials showed that this assumption was wrong [1]. Thus, we do not routinely recommend lung cancer screening today, although additional trials examining its efficacy are ongoing. The example of lung cancer screening serves to illustrate why it is necessary to first obtain evidence concerning the efficacy of cancer screening, before implementing it into clinical practice.