Most women who undertake mammography screening are given peace of mind from knowing they are breast-cancer free. Among women aged 40 to 49 years, 631 of the 10,000 mammograms will be abnormal resulting in 549 women being recalled at least once. After further testing, 533 abnormal screens will result in no breast cancer and 16 cancers will be detected. Three post-screen cancers will be diagnosed between rounds of screening.