Abstract
Breast cancer screening by mammography is widely used. The diagnostic accuracy is limited, with a positive predictive value of 16%. Therefore, a stepwise investigation, with repeat mammography and confirmation by pathology, is usually proposed. Although this stepwise investigation intends to avoid overtreatment, the many false positives result in unnecessary fear and diagnostic surgery in many women. The false negatives are not known since these women have not been investigated. Given the estimated low risk of missing breast cancer and the slow growth, repeating a screening mammography every two years is sufficient. The false positive screening results, increase with breast density, and breast density increases when hormone replacement therapy (HRT) is given. It, therefore, is suggested to use clinical judgment and stop HRT for 3 to 6 months before repeating the mammography instead of starting immediately a stepwise investigation in all women.