Many of the women who believe that their lives were saved by mammography screenings actually had so-called “IDLE” cancers (indolent lesions of epithelial origin), which would not have progressed before they died of other causes. Meanwhile, the very aggressive cancers, which are most likely to prove fatal, tend to present as “interval” cancers that appear between screenings.
很多相信乳腺X光造影筛查挽救了自己生命的女性实际患上的是所谓“无效”癌（源于上皮组织的无痛病变），这些病变直到她们因其他原因去世都不会有任何发展。此外，最有可能致命的攻击型癌症往往以“筛查”间期癌的形式存在。对最致命的病例进行定期筛查不会带来多大差别。