Breast cancer screening: should tomosynthesis replace digital mammography?

Abstract

Another spirited debate has ensued over the benefits of breast cancer screening,1 freshly stimulated by the recent publication of the 25-year follow-up results of the Canadian National Breast Screening Study (CNBSS) that showed no difference in breast cancer–related mortality in screened women vs controls.2 This latest controversy developed even though the CNBSS is the only one of 8 randomized clinical trials of screening mammography that failed to find a reduction in mortality,3 and despite substantial and well-described limitations in the CNBSS methods,4 including poor image quality and problems in the randomization schema that created a screened cohort with more large palpable cancers than the control group. Fourteen more recent studies published between 2001 and 2010 using more modern technology have shown a 25% to 50% reduction in breast cancer–related mortality for women aged 40 to 74 years.5 In the interval since the randomized trials of screening and with the demonstration of improved diagnostic accuracy for women with dense breasts,6 digital mammography has supplanted film mammography as the screening technology of choice,7 and treatment of breast cancer has improved substantially.8