It's unfortunate that Ms. Weeks has consulted such biased sources as the Canadian Task Force on Preventative Health, and the authors of the Canadian National Breast Screening trial for her article. The "compelling evidence" to which she refers regarding over-diagnosis has been shown to be exaggerated, based on false assumptions. Women need to know that in Canada, women who attend screening mammography are 40% less likely to die of breast cancer than women who do not. Mammography is not perfect, and is particularly weak in women with dense breasts. These women can benefit by supplementary breast ultrasound: in addition to, NOT instead of mammography. In these women, ultrasound can double the cancer detection rate, and finds small, invasive, node negative cancers that are missed on mammograms and are still too small to feel. A randomized trial of screening ultrasound in Japan has already demonstrated fewer interval cancers in the women having ultrasound.